Core-Shell Magnetoactive PHB/Gelatin/Magnetite Composite Electrospun Scaffolds for Biomedical Applications

Abstract

Novel hybrid magnetoactive composite scaffolds based on poly(3-hydroxybutyrate) (PHB), gelatin, and magnetite (Fe3O4) were fabricated by electrospinning. The morphology, structure, phase composition, and magnetic properties of composite scaffolds were studied. Fabrication procedures of PHB/gelatin and PHB/gelatin/Fe3O4 scaffolds resulted in the formation of both core-shell and ribbon-shaped structure of the fibers. In case of hybrid PHB/gelatin/Fe3O4 scaffolds submicron-sized Fe3O4 particles were observed in the surface layers of the fibers. The X-ray photoelectron spectroscopy results allowed the presence of gelatin on the fiber surface (N/C ratio–0.11) to be revealed. Incubation of the composite scaffolds in saline for 3 h decreased the amount of gelatin on the surface by more than ~75%. The differential scanning calorimetry results obtained for pure PHB scaffolds revealed a characteristic melting peak at 177.5 °C. The presence of gelatin in PHB/gelatin and PHB/gelatin/Fe3O4 scaffolds resulted in the decrease in melting temperature to 168–169 °C in comparison with pure PHB scaffolds due to the core-shell structure of the fibers. Hybrid scaffolds also demonstrated a decrease in crystallinity from 52.3% (PHB) to 16.9% (PHB/gelatin) and 9.2% (PHB/gelatin/Fe3O4). All the prepared scaffolds were non-toxic and saturation magnetization of the composite scaffolds with magnetite was 3.27 ± 0.22 emu/g, which makes them prospective candidates for usage in biomedical applications.

Comprehensive Study on the Reinforcement of Electrospun PHB Scaffolds with Composite Magnetic Fe3O4–rGO Fillers: Structure, Physico-Mechanical Properties, and Piezoelectric Response

“…The finding that the particle consists of agglomerates of magnetite crystallites is clearly illustrated in Figure B. The size of the crystallites of magnetite utilized in this study does not exceed 36.1 nm according to our previous publication . The greatest coercive force can be attained when the size of magnetite crystallites is equal to one domain…”

“…A further decrease in the crystallite size causes a sharp drop of H c to zero . The size of magnetite crystallites in the composite analyzed in this work is ∼36 nm . Nonetheless, the coercive force is 60 Oe because crystallites do not have an ideal spherical shape, and the deviation from sphericity for single-domain particles affects the coercive force .…”

“…Saturation magnetization of the magnetite particles used in the present study was evaluated in our previous work. 84 The saturation magnetization of the Fe 3 O 4 –rGO composites is 96.27 ± 1.42 emu/g, which is lower than that of pure Fe 3 O 4 owing to the presence of nonmagnetic rGO. Nonetheless, σ s is rather high.…”

“… 89 The size of magnetite crystallites in the composite analyzed in this work is ∼36 nm. 84 Nonetheless, the coercive force is 60 Oe because crystallites do not have an ideal spherical shape, and the deviation from sphericity for single-domain particles affects the coercive force. 88 The presence of rGO in composites also raises H c .…”

“…The size of the crystallites of magnetite utilized in this study does not exceed 36.1 nm according to our previous publication. 84 The greatest coercive force can be attained when the size of magnetite crystallites is equal to one domain. 86 10B) turned out to be 6.50 ± 0.39 and 6.83 ± 0.41 emu/g for the 27G and 21G needles, respectively.…”