Fabrication and Characterization of Bilayer Electrospun Polyvinyl alcohol/Polycaprolactone/Glutamine Membranes Integrated with 3D-Printed Polycaprolactone/Propolis Scaffolds for Skin Tissue Applications

Abstract

This study reports the development of a multifunctional bilayer wound dressing combining a 3D-printed polycaprolactone layer coated with propolis (PCL/PRP) and an electrospun polyvinyl alcohol/polycaprolactone/L-glutamine matrix (PVA/PCL/GLT). Scanning electron microscopy (SEM) confirmed a well-defined bilayer architecture, with porosities of 83.2 +/- 1.5 for the electrospun layer and 70.8 +/- 2.1 for the printed layer. The scaffold exhibited skin-relevant mechanical behavior, an optimal swelling ratio (16.90 +/- 0.52), favorable wettability (37.39 +/- 2.45 degrees), and a controlled degradation, with 20.18 +/- 1.99 weight loss after 72 h. Sustained release profiles were obtained for GLT and PRP, reaching 68.09 +/- 2.98 and 14.76 +/- 1.32, respectively, over 96 h, while the incorporation of PRP and GLT enhanced antibacterial performance. Fibroblast viability was significantly improved in the 4 GLT formulation, with metabolic activity reaching 124.69 +/- 2.37 (MTT assay). SEM micrographs after 7 days confirmed effective cell adhesion and spreading on the scaffold surfaces, with prominent filopodia indicating active cell-material interactions. Furthermore, scratch assay analysis demonstrated superior wound closure for the bilayer scaffold, with 83.25 +/- 3.57 closure after 24 h compared to 64.48 +/- 2.13 in the control group (P <= 0.05), reflecting enhanced fibroblast migration. Overall, the PCL/PRP-PVA/PCL/GLT (4 w/v) bilayer scaffold shows promising physicochemical and biological performance for wound healing applications.