Development of a Novel MR Colonography via Iron-Based Solid Lipid Nanoparticles

Abstract

Huiyang Wang,1,* Siqi Wang,2,* Xisong Zhu,3 Wenxiu Ding,4 Tianlun Shen,2 Hongjie Fan,1 Yanhua Zhang,5 Lijun Peng,6 Hong Yuan,6 Xiangrui Liu,7 Jun Ling,2 Jihong Sun1 1Department of Radiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, 310016, People’s Republic of China; 2MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, People’s Republic of China; 3Department of Radiology, Quzhou Central Hospital Affiliated to Zhejiang Chinese Medical University, Quzhou, 324002, People’s Republic of China; 4Department of Ultrasound Medicine, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310003, People’s Republic of China; 5Department of Pathology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, 310016, People’s Republic of China; 6College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310030, People’s Republic of China; 7Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, 310058, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jihong Sun, Department of Radiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, 310016, People’s Republic of China, Tel [phone], Fax [phone], Email [email protected] Jun Ling, MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, People’s Republic of China, Tel [phone], Fax [phone], Email [email protected]: To develop an iron-based solid lipid nanoparticle (SLN) absorbable by the intestinal wall and assess the differential diagnostic value of intestinal lesions in magnetic resonance imaging (MRI).Methods: SLNs were prepared with the simultaneous loading of trivalent Fe ions (Fe3+), levodopa methyl ester (DM), and fluorescein isothiocyanate (FITC). We evaluated the particle size, loading rate, encapsulation efficiency, and cytotoxicity of SLNs. The T1 contrast effects of the FeDM-FITC-SLNs and gadolinium-based contrast agent (GBCA) were compared in different mouse models: acute ulcerative colitis (AUC), chronic ulcerative colitis (CUC), colon adenocarcinoma (COAD), and normal control. MRI was performed in the same mouse with intravenous injection of GBCA on day 1 and enema of FeDM-FITC-SLNs on day 2. The signal-to-noise ratios (SNRs) were compared using one-way analysis of variance. Tissues were then collected for histology.Results: The average particle size of FeDM-FITC-SLN was 220 nm. The mean FeDM loading rate was 94.3%, and the encapsulation efficiency was 60.3%. The relaxivity was 4.02 mM− 1·s− 1. After enema with FeDM-FITC-SLNs, MRI showed the following contrast enhancement duration: AUC = COAD > normal > CUC. Confocal fluorescence microscopy confirmed that FeDM-FITC-SLNs were mainly distributed in the intestinal mucosa and tumor capsule.Conclusion: Iron-based SLNs are promising alternatives for contrast enhancement at T1-weighted MRI and will help in the differential diagnosis of intestinal bowel diseases (IBDs).Keywords: solid lipid nanoparticles, magnetic resonance imaging, contrast agent, ferric iron, intestinal bowel diseases

Keywords

• solid lipid nanoparticles
• magnetic resonance imaging
• contrast agent
• ferric iron
• intestinal bowel diseases.