Hybrid Biodegradable Nanocomposites Based on a Biopolyester Matrix and Magnetic Iron Oxide Nanoparticles: Structural, Magnetic, and Electronic Characteristics

The structural, electronic, and magnetic properties of iron oxide nanoparticles encapsulated in hybrid biodegradable therapeutic systems based on poly-3-hydroxybutyrate and chitosan are comprehensively studied using Mössbauer spectroscopy, X-ray diffraction, small-angle X-ray scattering, and macroscopic magnetization measurements. It is shown that iron oxide in concentrations of 4 and 8 wt % in the polymer matrix of magnetically isotropic and magnetoanisotropic systems exists in the form of nanosized ( d ≈ 7–8 nm) superparamagnetic clusters. Iron oxide clusters have the structure of a nonstoichiometric inverse spinel, intermediate between polymorphous modifications of Fe 3 O 4 and γ-Fe 2 O 3 .