Assessing hyperthermia performance of hybrid textile filaments: The impact of different heating agents

Abstract

The application of advanced textile materials functionalized with magnetic nanoparticles (MNP) has become increasingly important in tumor therapy. In this regard, the incorporation of MNP into polymeric filaments, so-called hybrid filaments, enables the development of magnetic heatable stents that, once implanted, are used to deliver therapeutic heat to the tumor site under the influence of an external alternating magnetic field (AMF). In this study, we investigate the hyperthermia performance of different hybrid filaments functionalized with MNP and discuss the relevant parameters influencing the heating efficiency such as MNP immobilization, agglomeration and magnetization as well as AMF settings. For this, three different MNP types (self-synthesized single domain MNP and two commercially available multi-domain MNP, BAYFERROX® and BNF-Starch) were incorporated in polypropylene filaments by melt spinning. Their heating efficiency was assessed in dependence of the AMF amplitude. Because of the blocking of Brownian rotation and bigger effective anisotropy constant caused by MNP agglomeration inside the filaments, the heating efficiency of all hybrid filaments was smaller than that of the corresponding MNP dispersed in water. Nevertheless, in all cases the heating efficiency increased with magnetic field amplitude. The highest specific loss power (SLP) values were reached for the self-synthesized particles at lower magnetic field amplitudes (<25 kA/m) and for BNF-Starch particles at high magnetic field amplitudes (>25 kA/m). This is caused by the higher anisotropy constant of the BNF-Starch particles and their collective magnetic response at higher magnetic field amplitudes.