Tuning mechanical behavior of spun nanofibrous materials based on polylactic acid/magnetite-nanoparticles for biomedical purposes

The design of magnetic polymer-based materials made of submicrometric fibers for different applications, such as wound healing, hyperthermia for cancer treatment, and scaffolds for tissue engineering, involves understanding key factors such as size and alignment of the fibers, together with molecular structure and composition. In this work, nanofibrous systems with potential medical applications based on Polylactic acid (PLA) filled with magnetite nanoparticles (Fe 3 O 4 -Np), were prepared by two methods, electrospinning (ES) and solution blow spinning (SBS). Their mechanical behaviors were studied through an in-depth analysis of results from tensile tests. Making use of fibrillar models, several factors have been considered when interpreting the mechanical properties of the materials, i) the morphology, studied by scanning electron microscopy (SEM); ii) the structure, studied by X-ray diffraction; iii) composition of the materials in terms of the concentration of Fe 3 O 4 -Np; iv) spinning conditions, and v) direction of application of the mechanical load. Both size and preferential orientation of fibers (conditioned by the spinning conditions and nanoparticles concentration) influence the mechanical behavior of the nanofibrous PLA/Fe 3 O 4 -Np materials. A fiber core-shell model is proposed to explain the mechanical results. It is demonstrated that with an adequate morphology design, wide ranges of mechanical behaviors can be achieved to allow these materials to properly adapt to any biological substrate. • Understanding morphology influence on polymer nanocomposite fibrous materials. • PLA/Fe 3 O 4 -Np fibers prepared via ES and SBS were analyzed for tensile properties. • Fiber size, alignment, and nanofiller influence the mechanical behavior. • Presence of nanoparticles induces morphology changes of the fibrous materials. • Mechanical properties are explained using a core-shell fiber model.