skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • Synthesis of BSA-Coated Iron Oxide Nanoparticles with Size Control for High-Performance T1 Contrast Agents in Magnetic Resonance Imaging
Title: Synthesis of BSA-Coated Iron Oxide Nanoparticles with Size Control for High-Performance T1 Contrast Agents in Magnetic Resonance Imaging
The excellent biocompatibility and favorable physicochemical properties of iron oxide nanoparticles have made them attractive candidates for magnetic resonance imaging. However, it remains challenging to synthesize high-performance T1 contrast agents with controlled sizes and biocompatible coating materials. In this study, we demonstrate a simple and environmentally friendly approach for synthesizing ultra-small iron oxide nanoparticles using bovine serum albumin (BSA) as a template. Following synthesis, the iron oxide nanoparticles (Fe3O4) were oxidized to Fe2O3 via the addition of hydrogen peroxide, which resulted in enhanced T1-weighted magnetic resonance contrast. The use of BSA not only stabilized the nanoparticles but also enabled precise control over nanoparticle size by adjusting the Fe-to-BSA molar ratio. This method yielded highly uniform and crystalline ultra-small nanoparticles ranging from approximately 3.7 to 7.9 nm in diameter. The T1 contrast performance of the Fe2O3@BSA nanoparticles was evaluated at 3 T magnetic field. Among the synthesized samples, nanoparticles with sizes of 4.6 nm exhibited the strongest T1 contrast enhancement along with low r2/r1 ratios. These features highlight their potential as promising alternatives to gadolinium-based contrast agents. In addition to their superior performance, this synthesis method is low-cost and non-toxic, making it suitable for scalable biomedical applications.  more » « less
Award ID(s):
2144790
PAR ID:
10673529
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
Biomolecules
Date Published:
Journal Name:
Biomolecules
Volume:
16
Issue:
3
ISSN:
2218-273X
Page Range / eLocation ID:
478
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; (, Scientific Reports)
    We have investigated the efficacy of superparamagnetic iron oxide nanoparticles (SPIONs) as positive T1 contrast agents for low-field magnetic resonance imaging (MRI) at 64 millitesla (mT). Iron oxide-based agents, such as the FDA-approved ferumoxytol, were measured using a variety of techniques to evaluate T1 contrast at 64 mT. Additionally, we characterized monodispersed carboxylic acid-coated SPIONs with a range of diameters (4.9–15.7 nm) in order to understand size-dependent properties of T1 contrast at low-field. MRI contrast properties were measured using 64 mT MRI, magnetometry, and nuclear magnetic resonance dispersion (NMRD). We also measured MRI contrast at 3 T to provide comparison to a standard clinical field strength. SPIONs have the capacity to perform well as T1 contrast agents at 64 mT, with measured longitudinal relaxivity (r1) values of up to 67 L mmol−1 s−1, more than an order of magnitude higher than corresponding r1 values at 3 T. The particles exhibit size-dependent longitudinal relaxivities and outperform a commercial Gd-based agent (gadobenate dimeglumine) by more than eight-fold at physiological temperatures. Additionally, we characterize the ratio of transverse to longitudinal relaxivity, r2/r1 and find that it is ~ 1 for the SPION based agents at 64 mT, indicating a favorable balance of relaxivities for T1-weighted contrast imaging. We also correlate the magnetic and structural properties of the particles with models of nanoparticle relaxivity to understand generation of T1 contrast. These experiments show that SPIONs, at low fields being targeted for point-of-care low-field MRI systems, have a unique combination of magnetic and structural properties that produce large T1 relaxivities. 
    more » « less
  2. ; ; ; ; ; ; ; ; ; (, Nanoscale)
    The direct synthesis of highly water-soluble nanoparticles has attracted intensive interest, but systematic size control has not been reported. Here, we developed a general method for synthesizing monodisperse water-soluble iron oxide nanoparticles with nanometer-scale size increments from 4 nm to 13 nm in a single reaction. Precise size control was achieved by continuous growth in an amphiphilic solvent, diethylene glycol (DEG), where the growth step was separated from the nucleation step by sequential addition of a reactant. There was only one reactant in the synthesis and no need for additional capping agents and reducing agents. This study reveals the “living growth” character of iron oxide nanoparticles synthesised in an amphiphilic solvent. The synthetic method shows high reproducibility. The as-prepared iron oxide nanoparticles are extremely water soluble without any surface modification. Surprisingly, the synthesized 9 nm iron oxide nanoparticles exhibit extremely high transversal and longitudinal relaxivities of 425 mM −1 s −1 and 32 mM −1 s −1 respectively, which is among the highest transversal relaxivity in the literature for sub-10 nm spherical nanoparticles. This study will not only shed light on the continuous growth phenomenon of iron oxide nanoparticles in an amphiphilic solvent, but could also stimulate the synthesis and application of iron oxide nanoparticles. The continuous growth method could be further extended to other materials for the controlled synthesis of water-soluble nanoparticles. 
    more » « less
  3. ; ; ; ; ; ; ; ; ; ; et al (, Small)
    Abstract Iron oxide nanoparticles (IONPs) are widely used for biomedical applications due to their unique magnetic properties and biocompatibility. However, the controlled synthesis of IONPs with tunable particle sizes and crystallite/grain sizes to achieve desired magnetic functionalities across single‐domain and multi‐domain size ranges remains an important challenge. Here, a facile synthetic method is used to produce iron oxide nanospheres (IONSs) with controllable size and crystallinity for magnetic tunability. First, highly crystalline Fe3O4IONSs (crystallite sizes above 24 nm) having an average diameter of 50 to 400 nm are synthesized with enhanced ferrimagnetic properties. The magnetic properties of these highly crystalline IONSs are comparable to those of their nanocube counterparts, which typically possess superior magnetic properties. Second, the crystallite size can be widely tuned from 37 to 10 nm while maintaining the overall particle diameter, thereby allowing precise manipulation from the ferrimagnetic to the superparamagnetic state. In addition, demonstrations of reaction scale‐up and the proposed growth mechanism of the IONSs are presented. This study highlights the pivotal role of crystal size in controlling the magnetic properties of IONSs and offers a viable means to produce IONSs with magnetic properties desirable for wider applications in sensors, electronics, energy, environmental remediation, and biomedicine. 
    more » « less
  4. ; ; ; ; (, Journal of materials science)
    We present an interdisciplinary overview of material engineering and emerging applications of iron oxide nanoparticles. We discuss material engineering of nanoparticles in the broadest sense, emphasizing size and shape control, large-area self-assembly, composite/hybrid structures, and surface engineering. This is followed by a discussion of several nontraditional, emerging applications of iron oxide nanoparticles, including nanoparticle lithography, magnetic particle imaging, magnetic guided drug delivery, and positive contrast agents for magnetic resonance imaging. We conclude with a succinct discussion of the pharmacokinetics pathways of iron oxide nanoparticles in the human body—an important and required practical consideration for any in vivo biomedical application, followed by a brief outlook of the field. 
    more » « less
  5. ; ; (, Carbon)
    Liu, Chang (Ed.)
    The synthesis of carbon nanotubes (CNTs) requires well-defined catalyst nanoparticles that can influence both diameter and chirality. Herein, catalyst nanoparticles containing both the catalyst and catalyst support material were developed. Bimetallic aluminum oxide–iron oxide (AlOx–Fe2O3) nanorice was synthesized from a mixture containing both aluminum and iron oleate precursors in the solution phase. The nanoparticles were assembled as a monolayer film on a silicon oxide (SiO2) substrate via organic linker molecules to synthesize vertically aligned carbon nanotubes (VA-CNTs). Microscopic and spectroscopic characterization of the premade catalyst nanoparticles and monolayer film assembly revealed the quality of the nanoscale assembly, which facilitated the successful growth of VA-CNTs. The length of the CNTs synthesized using these AlOx–Fe2O3 nanorice catalyst nanoparticles surpassed that of previously reported CNTs grown on bare SiO2 surfaces without oxide buffer layers. In addition, the CNTs appeared to be directly bonded/connected to the SiO2 substrate, suggesting CNT formation via the tip-growth mechanism. The effects of growth temperature and catalyst reduction time were evaluated to obtain high-yield VA-CNTs. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Text Encoded Conversion
  • XML
  • Save / Share this Record
  • Send to Email