Chitosan/Mesoporous bioactive glass nanoparticle coatings on PLA: a comparative study between dip-coating and electrophoretic deposition

Abstract This study aims to evaluate chitosan/mesoporous bioactive glass nanoparticle (MBGN) coatings on PLA by comparing two deposition techniques: dip-coating (DP) and electrophoretic deposition (EPD). Two different geometries were analyzed: flat surface and 3D scaffold, both obtained by a filament-based 3D printer. The homogeneity of the coating on the scaffold structure was evaluated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analysis. For the wettability analysis and coating adhesion tape test, deposition was performed on flat surfaces. In the EPD process, a homogeneous film was formed that uniformly covered the surface. It was observed that larger agglomerates formed on the surface coated by dip-coating. These differences in the morphology affected the coating adhesion and the wettability measured by contact angle. The deposition onto the 3D scaffold structure also showed significant differences. The deposition by dip-coating was concentrated on the surface of the filaments, with almost no particles observed on the filament’s lateral edges and on the cross-section region, regardless of the treatment duration. XPS indicated that the samples deposited by EPD contained a higher number of particles compared to those deposited by dip-coating. Therefore, we conclude that EPD has great potential to obtain chitosan-based coatings not only on conductive substrates but also on non-conductive substrates with complex geometries, such as PLA scaffolds.