Preparation and Microscopic Mechanical Characterization of L-Methionine-Based Polyphosphazene Fibrous Mats for Vascular Tissue Engineering

This study investigates the mechanical properties, degradation behavior, and biocompatibility of poly[(α-amino acid ester) phosphazene] electrospun fibers based on the ethyl ester of L-methionine (PαAPz-M), a material with potential applications in tissue engineering. We utilized atomic force microscopy (AFM) to evaluate the fiber mechanical characteristics and calculate its Young’s modulus, revealing it to closely mimic the stiffness of a natural extracellular matrix (ECM). We also studied the degradation behavior of PαAPz-M scaffolds over 21 days, showing that they maintain the highly porous structure required for tissue engineering. Further evaluation of mesenchymal multipotent 10T1/2 cell and mesenchymal stem cell (MSC) behavior on the scaffolds demonstrated significant cell viability, proliferation, and successful MSC differentiation into smooth muscle cells. Expression of collagen and elastin by MSCs on the fiber mats highlighted potential ECM formation during scaffold degradation, confirming PαAPz-M as a promising material for vascular tissue engineering.