Assessment of the structural and histopathological challenges of binary electrospun PET-based nanofibers for tissue engineering applications

Tissue engineering and regenerative medicine aim to address tissue lesions and organ degenerations, enhancing clinical outcomes by restoring damaged tissues and functionalities. Recent progress in materials science and medicine has led to the development of regenerative engineering, revolutionizing the production of polymeric artificial scaffolds by electrospinning method, which mimic the extracellular matrix (ECM). Polyurethane (PU) is recognized for its elastic nature, comprising soft and hard segments, and possesses bioactive as well as biocompatible properties. Polycaprolactone (PCL), on the other hand, is a non-toxic polymer with a viscous nature, known for its favorable mechanical properties. This study focuses on the comprehensive histological evaluation of binary electrospun PET-based nanofiber scaffolds, as widely used in tissue engineering. The structural analysis involved FE-SEM imaging, porosity measurement, FTIR, and DSC examinations. In vitro assessments included degradation rates, water uptake, cell viability, morphological cell examination, and cell attachment studies. Additionally, scaffolds were subcutaneously implanted in rats for pathological examination. After a 30 days implantation period, histological and pathological parameters such as edema, inflammation, foreign body giant cell reaction, fibrosis, necrosis, and calcification were evaluated. The results highlight the successful application of blend electrospinning in producing PET/PCL and PET/PU nanofiber scaffolds with various composition ratios. FE-SEM imaging revealed uniform nanostructures without bead formation. Histological analysis showed favorable biocompatibility, with the PET/PCL (25:75) composition demonstrating superior structural characteristics compared to other ratios. The cell studies indicated that PET-based nanofiber scaffolds exhibited suitable cell viability and attachment, underscoring their potential for tissue engineering applications.