In Situ One-Pot Synthesis of Fe₂O₃@BSA Core-Shell Nanoparticles as Enhanced T₁-Weighted Magnetic Resonance Imagine Contrast Agents

Abstract

Ultra-small-sized iron oxide nanoparticles with good biocompatibility are regarded as promising alternatives for the gadolinium-based contrast agents, which are widely used as a positive contrast agent in magnetic resonance imaging (MRI). However, the current preparation of the iron oxide magnetic nanoparticles with small sizes usually involves organic solvents, increasing the complexity of hydrophilic ligand replacement and reducing the synthesis efficiency. It remains a great challenge to explore new iron oxide nanoparticles with good biocompatibility and a high T 1 contrast effect. Here, we reported a cage-like protein architecture self-assembled by approximately 6−7 BSA (bovine serum albumin) subunits. The BSA nanocage was then used as a biotemplate to synthesize uniformed and monodispersed Fe 2 O 3 @BSA nanoparticles with ultra-small sizes (∼3.5 nm). The Fe 2 O 3 @BSA nanoparticle showed a high r 1 value of 6.8 mM −1 s −1 and a low r 2 /r 1 ratio of 10.6 at a 3 T magnetic field. Compared to Gd-DTPA, the brighter signal and prolonged angiographic effect of Fe 2 O 3 @BSA nanoparticles could greatly benefit steady-state and high-resolution imaging. The further in vivo and in vitro assessments of stability, toxicity, and renal clearance indicated a substantial potential as a T 1 contrast agent in preclinical MRI.

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

“…In addition, the stretching vibration peak of Fe–O at 604.5 cm −1 can be seen from the FT-IR of ES-MION9, but not in the FT-IR of PASP, indicating the existence of iron in ES-MION9. These results prove the successful synthesis of Fe 3 O 4 [ 38 ]. Additional file 1 : Fig.…”

Recent advances in engineering iron oxide nanoparticles for effective magnetic resonance imaging

“…Since coordination number of iron ion is constant, the method to optimize the q is directly increasing the number of iron ions on the surface or introducing other magnetic ions with large amounts of unpaired electrons. Thanks to the controllable synthesis and development of new generation of surface ligands, various IONP with high surface-to-volume ratio, specific composition, and optimal surface coating have been developed to show high T 1 contrast and exhibit potential to achieve accurate tumor contrast imaging [ [48] , [49] , [50] ]. Recently, an undesirable structure, that is the presence of undesirable Fe (II) ion on the surface of IONP, have been noticed.…”

Facile synthesis of superparamagnetic nickel-doped iron oxide nanoparticles as high-performance T1 contrast agents for magnetic resonance imaging

“…The results showed that Rh123@NiIO NPs were quickly metabolized through the kidneys and accumulated in the bladder and excreted from the body, which is likely due to the fact that the nanoparticles are less than the renal filtration threshold (6–8 nm). 39,50 Fluorescence imaging demonstrated the successful functionalization of NiIO NPs, further demonstrating that NiIO NPs are well metabolized in vivo . Therefore, NiIO NPs have great potential as multimode imaging nanoprobes, and the design idea of this integrated nanoparticle platform is of great significance for accurate clinical diagnosis.…”

“…The blocking temperatures at the peak of the FC/ZFC curves of NiIO NPs were all below 125 K, which was attributed to the extremely small size of nanoparticles. 14,39,40…”