Toxicity and Tissue Distribution of Magnetic Nanoparticles in Mice

TLDR

Nanoparticle technology offers diverse scientific benefits but also poses potential human and environmental risks, making it essential to understand their biological fate and toxicity. The study aimed to evaluate the biological distribution and potential toxicity of magnetic nanoparticles for applications in life science. The authors synthesized silica‑overcoated magnetic nanoparticles containing rhodamine B isothiocyanate and used 50‑nm thick MNPs@SiO2(RITC) as a model nanomaterial. After 4 weeks of intraperitoneal administration, 50‑nm magnetic nanoparticles penetrated the blood–brain barrier and remained in various organs without causing apparent toxicity, indicating they are safe under the experimental conditions.

Abstract

The development of technology enables the reduction of material size in science. The use of particle reduction in size from micro to nanoscale not only provides benefits to diverse scientific fields but also poses potential risks to humans and the environment. For the successful application of nanomaterials in bioscience, it is essential to understand the biological fate and potential toxicity of nanoparticles. The aim of this study was to evaluate the biological distribution as well as the potential toxicity of magnetic nanoparticles to enable their diverse applications in life science, such as drug development, protein detection, and gene delivery. We recently synthesized biocompatible silica-overcoated magnetic nanoparticles containing rhodamine B isothiocyanate (RITC) within a silica shell of controllable thickness [MNPs@SiO2(RITC)]. In this study, the MNPs@SiO2(RITC) with 50-nm thickness were used as a model nanomaterial. After intraperitoneal administration of MNPs@SiO2(RITC) for 4 weeks into mice, the nanoparticles were detected in the brain, indicating that such nanosized materials can penetrate blood–brain barrier (BBB) without disturbing its function or producing apparent toxicity. After a 4-week observation, MNPs@SiO2(RITC) was still present in various organs without causing apparent toxicity. Taken together, our results demonstrated that magnetic nanoparticles of 50-nm size did not cause apparent toxicity under the experimental conditions of this study.