Biodegradable and biocompatible exceedingly small magnetic iron oxide nanoparticles for T1-weighted magnetic resonance imaging of tumors

作者：Lu, Xuanyi; Zhou, Huimin; Liang, Zhiyu; Feng, Jie; Lu, Yudie; Huang, Lin; Qiu, Xiaozhong^*; Xu, Yikai^*; Shen, Zheyu^*

来源：JOURNAL OF NANOBIOTECHNOLOGY, 2022, 20(1): 350.

DOI：10.1186/s12951-022-01562-y

• Magnetic resonance imaging (MRI)
• Contrast agents (CAs)
• Exceedingly small magnetic iron oxide nanoparticles (ES-MIONs)
• Poly (aspartic acid) (PASP)
• Biodegradable

Magnetic resonance imaging (MRI) has been widely using in clinical diagnosis, and contrast agents (CAs) can improve the sensitivity MRI. To overcome the problems of commercial Gd chelates-based T-1 CAs, commercial magnetic iron oxide nanoparticles (MIONs)-based T-2 CAs, and reported exceedingly small MIONs (ES-MIONs)-based T-1 CAs, in this study, a facile co-precipitation method was developed to synthesize biodegradable and biocompatible ES-MIONs with excellent water-dispersibility using poly (aspartic acid) (PASP) as a stabilizer for T-1-weighted MRI of tumors. After optimization of the synthesis conditions, the final obtained ES-MION9 with 3.7 nm of diameter has a high r(1) value (7.0 +/- 0.4 mM(-1) s(-1)) and a low r(2)/r(1) ratio (4.9 +/- 0.6) at 3.0 T. The ES-MION9 has excellent water dispersibility because of the excessive -COOH from the stabilizer PASP. The pharmacokinetics and biodistribution of ES-MION9 in vivo demonstrate the better tumor targetability and MRI time window of ES-MION9 than commercial Gd chelates. T-1-weighted MR images of aqueous solutions, cells and tumor-bearing mice at 3.0 T or 7.0 T demonstrate that our ES-MION9 has a stronger capability of enhancing the MRI contrast comparing with the commercial Gd chelates. The MTT assay, live/dead staining of cells, and H&E-staining indicate the non-toxicity and biosafety of our ES-MION9. Consequently, the biodegradable and biocompatible ES-MION9 with excellent water-dispersibility is an ideal T-1-weighted CAs with promising translational possibility to compete with the commercial Gd chelates.

• 单位
  南方医科大学