Comparative Study of Silk-Based Magnetic Materials: Effect of Magnetic Particle Types on the Protein Structure and Biomaterial Properties

Abstract

This study investigates combining the good biocompatibility and flexibility of silk protein with three types of widely used magnetic nanoparticles to comparatively explore their structures, properties and potential applications in the sustainability and biomaterial fields. The secondary structure of silk protein was quantitatively studied by infrared spectroscopy. It was found that magnetite (Fe3O4) and barium hexaferrite (BaFe12O19) can prohibit β-sheet crystal due to strong coordination bonding between Fe3+ ions and carboxylate ions on silk fibroin chains where cobalt particles showed minimal effect. This was confirmed by thermal analysis, where a high temperature degradation peak was found above 640 °C in both Fe3O4 and BaFe12O19 samples. This was consistent with the magnetization studies that indicated that part of the Fe in the Fe3O4 and BaFe12O19 was no longer magnetic in the composite, presumably forming new phases. All three types of magnetic composites films maintained high magnetization, showing potential applications in MRI imaging, tissue regeneration, magnetic hyperthermia and controlled drug delivery in the future.

3D-Printing of Silk Nanofibrils Reinforced Alginate for Soft Tissue Engineering

“…Inspired by these studies, the hydrogen bonding between the N-H group of SNF and the COOH group of the alginate could lead to an enhanced shape fidelity. In addition, according to Equation (1), the β-sheet content of SNF was 48 ± 1%, which was comparable with previous studies [ 49 , 50 , 51 ]. For instance, Farasatkia et al [ 48 ] found that the β-sheet content of SNF synthesized using the acid-salt method was 53 ± 2%.…”

“…However, β-sheet content was decreased to 33 ± 2% after hybrid hydrogel formation, indicating that the alginate could also vaguely improve the random coil formation. Similarly, Xue et al [ 51 ] also found that the β-sheet content of SNF decreased with an increase in magnetic content, while the random coil content improved.…”

Degradable silk-based soft actuators with magnetic responsiveness

“…69 The incorporation of the Fe 3 O 4 NPs into the films induced a slight decrease of β-sheet content which is likely due to the strong coordination bonding between silk proteins and Fe 3 O 4 NPs. 70 In contrast, the contents of random coil/helix and β-turn structures showed slight increases after the introduction of Fe 3 O 4 NPs.…”