Development of europium doped core-shell silica cobalt ferrite functionalized nanoparticles for magnetic resonance imaging

Abstract

The size, shape and chemical composition of europium (Eu3+) cobalt ferrite (CFEu) nanoparticles were optimized for use as a “multimodal imaging nanoprobe” for combined fluorescence and magnetic resonance bioimaging. Doping Eu3+ ions into a CF structure imparts unique bioimaging and magnetic properties to the nanostructure that can be used for real-time screening of targeted nanoformulations for tissue biodistribution assessment. The CFEu nanoparticles (size ~7.2 nm) were prepared by solvothermal techniques and encapsulated into poloxamer 407-coated mesoporous silica (Si-P407) to form superparamagnetic monodisperse Si-CFEu nanoparticles with a size of ~ 140 nm. Folic acid (FA) nanoparticle decoration (FA-Si-CFEu, size ~ 140 nm) facilitated monocyte-derived macrophage (MDM) targeting. FA-Si-CFEu MDM uptake and retention was higher than seen with Si-CFEu nanoparticles. The transverse relaxivity of both Si-CFEu and FA-Si-CFEu particles were r2= 433.42 mM−1s−1 and r2= 419.52 mM−1s−1 (in saline) and r2= 736.57 mM−1s−1 and r2= 814.41 mM−1s−1 (in MDM), respectively. The results were greater than a log order-of-magnitude than what was observed at replicate iron concentrations for ultrasmall superparamagnetic iron oxide (USPIO) particles (r2= 31.15 mM−1s−1 in saline) and paralleled data sets obtained for T2 magnetic resonance imaging. We now provide a developmental opportunity to employ these novel particles for theranostic drug distribution and efficacy evaluations.

Bioimaging predictors of rilpivirine biodistribution and antiretroviral activities

“…Monodisperse and high quality crystalline EuCF nanocrystals were synthesized and characterized via state of the art techniques as previously described [22]. Production of chelate free, non-leachable and highly stable radiolabeled 111 InEuCF nanocrystals was accomplished by intrinsic co-doping of the 111 In radionuclide along with europium into the cobalt ferrite lattice structure.…”

“…The newly minted drug particles facilitated real-time non-invasive detection of drug and antiretroviral drug biodistribution and screening. These findings forge a significant improvement over first generation EuCF-PCL particles [22] by extending ARV encapsulations and bioimaging capabilities to assess drug biodistribution. Indeed, these particles improve signal intensities from both single photon emission computed tomography (SPECT/CT) and magnetic resonance imaging (MRI) in order to accurately predict drug distribution.…”

Long-acting slow effective release antiretroviral therapy

“…One additional limitation of this system is related to the low sensitivity of the SMART particle system. To overcome these limitations, we recently explored combined fluorescence and magnetic properties of europium to generate MRI sensitive cobalt ferrite europium core shell silica magnetic nanoparticles [19]. The resultant monodispersed CFEus formed crystals with a unique inverse-spinel structure and particle sizes equivalent to conventional nanoART.…”

Novel functionalized nanoparticles for tumor-targeting co-delivery of doxorubicin and siRNA to enhance cancer therapy

“…3 To improve these shortcomings, a large number of nanoscale drug carriers, such as polymeric nanomicelles, inorganic nanoparticles and liposomes and so on, have been developed to achieve the tumor-targeted delivery of chemotherapeutic drugs. [4][5][6] Among them, selenium nanoparticles (SeNPs) have received an increasing attention as drug carriers owing to their biocompatibility, low toxicity, simple synthesis process, in vivo degradability and excellent chemopreventive effects. 7 Selenium is a mineral trace element of fundamental importance to humans and animals.…”