Biocompatible superparamagnetic core-shell nanoparticles for potential use in hyperthermia-enabled drug release and as an enhanced contrast agent

Abstract

Superparamagnetic iron oxide nanoparticles (SPIONs) and core-shell type nanoparticles, consisting of SPIONs coated with mesoporous silica and/or lipid, were synthesised and tested for their potential theranostic applications in drug delivery, magnetic hyperthermia and as a contrast agent. Transmission Electron Microscopy (TEM) confirmed the size of bare and coated SPIONs was in the range of 5–20 nm and 100–200 nm respectively. The superparamagnetic nature of all the prepared nanomaterials as indicated by Vibrating Sample Magnetometry (VSM) and their heating properties under an AC field confirm their potential for hyperthermia applications. Scanning Column Magnetometry (SCM) data showed that extrusion of bare-SPION (b-SPION) dispersions through a 100 nm polycarbonate membrane significantly improved the dispersion stability of the sample. No sedimentation was apparent after 18 h compared to a pre-extrusion estimate of 43% settled at the bottom of the tube over the same time. Lipid coating also enhanced dispersion stability. Transversal relaxation time (T2) measurements for the nanoparticles, using a bench-top relaxometer, displayed a significantly lower value of 46 ms, with a narrow relaxation time distribution, for lipid silica coated SPIONs (Lip-SiSPIONs) as compared to that of 1316 ms for the b-SPIONs. Entrapment efficiency of the anticancer drug, Doxorubicin (DOX) for Lip-SPIONs was observed to be 35% which increased to 58% for Lip-SiSPIONs. Moreover, initial in-vitro cytotoxicity studies against human breast adenocarcinoma, MCF-7 cells showed that % cell viability increased from 57% for bSPIONs to 82% for Lip-SPIONs and to 87% for Lip-SiSPIONs. This suggests that silica and lipid coatings improve the biocompatibility of bSPIONs significantly and enhance the suitability of these particles as drug carriers. Hence, the magnetic nanomaterials prepared in this work have potential theranostic properties as a drug carrier for hyperthermia cancer therapy and also offer enhancement of contrast agent efficacy and a route to a significant increase in dispersion stability.

Green synthesis as a simple and rapid route to protein modified magnetic nanoparticles for use in the development of a fluorometric molecularly imprinted polymer-based assay for detection of myoglobin

“…The magnetization curves with S-like shape are symmetrical to the origin and there is near-zero hysteresis, with both remanence and coercivity approximately zero, indicating that the samples are predominantly superparamagnetic. The saturation magnetization values of 38 emu g −1 (SPION@CHO) and 75 emu g −1 (SPION (bare)) are lower than the ferrimagnetic bulk value of 92 emu g −1 [ 70 ] and is expected when in a superparamagnetic state at particle sizes <100 nm, as is the case here [ 71 ]. However, the values are still high enough for easy and rapid separation when under an external magnetic field.…”

Metal-Based Nanomaterials: Work as Drugs and Carriers against Viral Infections

“…However, vaccines for injection have biological activity, and instability in transportation and storage is still an open question. Hence, many scholars have developed numerous carrier materials, such as colloids [ 40 ], magnetic nanomaterials [ 41 ], inorganic nanomaterials [ 42 ], and metal organic framework materials [ 43 ], to increase the loading rate of drug molecules by high biocompatibility and high specific surface area of the carrier material. Thereby, the carrier nanomaterial increases the uptake rate of the cell to the drug, and enhances the stability of the vaccine and the immune response of the body.…”

The Combination of Liposomes and Metallic Nanoparticles as Multifunctional Nanostructures in the Therapy and Medical Imaging—A Review

“…The results provide perspectives for implementing both imaging and therapeutic agents into the PS-targeted liposomal platform. Recently, Patil-Sen et al [94] reported on the fabrication of a threecomponent composite-magnetoliposome consisting of a SPION-silica core-shell coated with mesoporous silica and/or outer lipid layer. The aim of the construction of those structures was to show their potential theragnostic applications in drug delivery and magnetic hyperthermia.…”