Fe-Doped Sol-Gel Glasses and Glass-Ceramics for Magnetic Hyperthermia.

Marta Miola,Barbara Onida,Enrica Verné,Francesco Baino,Federica Leone,Roberto Gerbaldo,Elisa Fiume,Francesco Laviano

doi:10.3390/ma11010173

Abstract

This work deals with the synthesis and characterization of novel Fe-containing sol-gel materials obtained by modifying the composition of a binary SiO2-CaO parent glass with the addition of Fe2O3. The effect of different processing conditions (calcination in air vs. argon flowing) on the formation of magnetic crystalline phases was investigated. The produced materials were analyzed from thermal (hot-stage microscopy, differential thermal analysis, and differential thermal calorimetry) and microstructural (X-ray diffraction) viewpoints to assess both the behavior upon heating and the development of crystalline phases. N2 adsorption–desorption measurements allowed determining that these materials have high surface area (40–120 m2/g) and mesoporous texture with mesopore size in the range of 18 to 30 nm. It was assessed that the magnetic properties can actually be tailored by controlling the Fe content and the environmental conditions (oxidant vs. inert atmosphere) during calcination. The glasses and glass-ceramics developed in this work show promise for applications in bone tissue healing which require the use of biocompatible magnetic implants able to elicit therapeutic actions, such as hyperthermia for bone cancer treatment.

Highlights

Magnetic materials represent advanced solutions suitable for a wide range of biomedical applications, according to their different magnetic responses to an applied external magnetic field [1].Specific applications of these materials include magnetic resonance imaging (MRI), magnetic stimulation, magnetic cell separation, active targeting for drug delivery applications, protein immobilization and hyperthermia for the treatment of malignant tumors [2,3,4].The most commonly used magnetic materials in biomedical applications are ferrimagnetic iron oxides, their acute toxicity and their still partially unknown fate in vivo limit their usage as implants in clinical practice [5]
The calcination process performed on 60S38C2Fe at 700 ◦ C in either air or argon did not induce the nucleation of any crystalline phases within the glassy matrix, suggesting that the environmental conditions of heat treatment play a secondary role in the devitrification process for this material
The role played by Fe2 O3 in promoting devitrification of silicate ternary glasses was deeply investigated by Poirier et al [32], who confirmed its greater effectiveness as devitrifying agent compared to other metal oxides (e.g., TiO2 )

Summary

Introduction

Magnetic materials represent advanced solutions suitable for a wide range of biomedical applications, according to their different magnetic responses to an applied external magnetic field [1].Specific applications of these materials include magnetic resonance imaging (MRI), magnetic stimulation, magnetic cell separation, active targeting for drug delivery applications, protein immobilization and hyperthermia for the treatment of malignant tumors [2,3,4].The most commonly used magnetic materials in biomedical applications are ferrimagnetic iron oxides (e.g., magnetite, Fe3 O4 ), their acute toxicity and their still partially unknown fate in vivo limit their usage as implants in clinical practice [5]. Magnetic materials represent advanced solutions suitable for a wide range of biomedical applications, according to their different magnetic responses to an applied external magnetic field [1]. Specific applications of these materials include magnetic resonance imaging (MRI), magnetic stimulation, magnetic cell separation, active targeting for drug delivery applications, protein immobilization and hyperthermia for the treatment of malignant tumors [2,3,4]. The most commonly used magnetic materials in biomedical applications are ferrimagnetic iron oxides (e.g., magnetite, Fe3 O4 ), their acute toxicity and their still partially unknown fate in vivo limit their usage as implants in clinical practice [5]. Malignant cells are selectively killed while being exposed to such temperatures because heat is slowly dissipated in cancerous tissues due to the lack

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Conclusion