Double-Layer Fatty Acid Nanoparticles as a Multiplatform for Diagnostics and Therapy

Abstract

Today, public health is one of the most important challenges in society. Cancer is the leading cause of death, so early diagnosis and localized treatments that minimize side effects are a priority. Magnetic nanoparticles have shown great potential as magnetic resonance imaging contrast agents, detection tags for in vitro biosensing, and mediators of heating in magnetic hyperthermia. One of the critical characteristics of nanoparticles to adjust to the biomedical needs of each application is their polymeric coating. Fatty acid coatings are known to contribute to colloidal stability and good surface crystalline quality. While monolayer coatings make the particles hydrophobic, a fatty acid double-layer renders them hydrophilic, and therefore suitable for use in body fluids. In addition, they provide the particles with functional chemical groups that allow their bioconjugation. This work analyzes three types of self-assembled bilayer fatty acid coatings of superparamagnetic iron oxide nanoparticles: oleic, lauric, and myristic acids. We characterize the particles magnetically and structurally and study their potential for resonance imaging, magnetic hyperthermia, and labeling for biosensing in lateral flow immunoassays. We found that the myristic acid sample reported a large r2 relaxivity, superior to existing iron-based commercial agents. For magnetic hyperthermia, a significant specific absorption rate value was obtained for the oleic sample. Finally, the lauric acid sample showed promising results for nanolabeling.

Magnetic Nanoclusters Increase the Sensitivity of Lateral Flow Immunoassays for Protein Detection: Application to Pneumolysin as a Biomarker for Streptococcus pneumoniae

“…The optimal concentration of neutravidin for the bioconjugation to the MNCs was 1 mg/mL. The magneto-inductive signal obtained with the sensing device was 1.8 mΩ•mm, outperforming the best previous results obtained with lauric acid-coated magnetic nanoclusters: 1.1 mΩ•mm for 2 mg/mL of neutravidin and 0.65 mΩ•mm for 1 mg/mL [47]. These results advised the use of the present MNCs for PLY detection.…”

“…The MNCs were evaluated in the magnetic sensor, resulting in a sensitivity of 3.12% per mg of MNCs, as defined in Equation (1), which is better than our best result obtained with similar particles, 2.60% per mg of oleic acid-coated magnetic nanoclusters [47]. The resolution of the system, defined as in Equation ( 2), reached only 71 ng of MNCs, outperforming the 186 ng than can be distinguished with the oleic acid-coated magnetic nanoclusters.…”

Ferrofluids and bio-ferrofluids: looking back and stepping forward

“…The lauric acid coated nanoclusters in aqueous bioferrofluids proved to be highly performant nanolabels for lateral flow immunoassays and their magnetic quantification. 755…”

“…The lauric acid coated nanoclusters in aqueous bioferrofluids proved to be highly performant nanolabels for lateral flow immunoassays and their magnetic quantification. 755 Ferrofluids due to their high magnetic field sensitivity, fluidity and optical fiber compatibility [756][757][758] are the basic component of various magneto-optic devices, 759 among them a large variety of magnetic field sensors exploiting specific field induced effects, such as birefringence, dichroism, Faraday rotation or refractive index variation 246,[760][761][762] and magnetic fluids coupled with optical fiber technology. 763 Magnetic field sensors were developed by combining magnetic fluids with an etched fiber Bragg grating, 764 with a Sagnac interferometer, 761,765 with a Mach-Zehnder interferometer and photonic crystal fiber, 766 and with a Michelson 767 or a Fabry-Pérot interferometer.…”

Recent advances in surface modification of micro- and nano-scale biomaterials with biological membranes and biomolecules

“…Fatty acid coatings can promote colloidal stability and enhance the surface crystalline quality of magnetic iron oxide NPs ( Bixner et al, 2015 ; Salvador et al, 2022 ). Sonication is used to coat magnetic NPs with fatty acids ( Argüelles-Pesqueira et al, 2018 ; Gupta et al, 2019 ).…”