Surface Modification of SPIONs in PHBV Microspheres for Biomedical Applications

Maizlinda I Idris,Harald Unterweger,Judith A Roether,Christoph Alexiou,Aldo R Boccaccini,Rainer Detsch,Jan Zaloga

doi:10.1038/s41598-018-25243-9

Abstract

Surface modification of superparamagnetic iron oxide nanoparticles (SPIONs) has been introduced with lauric acid and oleic acid via co-precipitation and thermal decomposition methods, respectively. This modification is required to increase the stability of SPIONs when incorporated in hydrophobic, biodegradable and biocompatible polymers such as poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). In this work, the solid-in-oil-in-water (S/O/W) emulsion-solvent extraction/evaporation method was utilized to fabricate magnetic polymer microspheres incorporating SPIONs in PHBV. The prepared magnetic PHBV microspheres exhibited particle sizes <1 µm. The presence of functional groups of lauric acid, oleic acid and iron oxide in the PHBV microspheres was confirmed by Fourier Transform Infrared spectroscopy (FTIR). X-ray diffraction (XRD) analysis was performed to further confirm the success of the combination of modified SPIONs and PHBV. Thermogravimetric analysis (TGA) indicated that PHBV microspheres were incorporated with SPIONsLauric as compared with SPIONsOleic. This was also proven via magnetic susceptibility measurement as a higher value of this magnetic property was detected for PHBV/SPIONsLauric microspheres. It was revealed that the magnetic PHBV microspheres were non-toxic when assessed with mouse embryotic fibroblast cells (MEF) at different concentrations of microspheres. These results confirmed that the fabricated magnetic PHBV microspheres are potential candidates for use in biomedical applications.

Highlights

Of superparamagnetic iron oxide nanoparticles (SPIONs) during preparation of magnetic microspheres, which is presented in the second part of the study
The surface morphology of PHBV microspheres and PHBV microspheres incorporated with SPIONsOleic was evaluated by scanning electron microscopy (SEM) (Fig. 1)
PHBV microspheres were fabricated with SPIONsLauric and SPIONsOleic at different mass ratios through the solid-in-oil-in-water (S/O/W) emulsion-solvent extraction/evaporation method

Summary

Introduction

Of SPIONs during preparation of magnetic microspheres, which is presented in the second part of the study. The surface of the SPIONs was modified with two types of fatty acid, namely lauric acid and oleic acid, through co-precipitation and thermal decomposition methods. The production of PHBV microspheres with modified SPIONs was chosen via emulsion-solvent extraction/evaporation method. This method has been described in detail by Li and co-authors[14]. A further goal of this investigation is to provide findings related to the chemical, structural, thermal and magnetic properties as well as in vitro biocompatibility of the prepared magnetic PHBV microspheres combined with SPIONs modified with lauric acid and oleic acid. As far as the authors know, these two types of modifications on SPIONs for their interaction with PHBV have not been investigated and compared before

Methods

Results

Conclusion