Влияние β-глицина на морфологию, кристаллическую структуру, свойства поверхности и пьезоэлектрический отклик полимерных нановолокон для тканевой инженерии

Abstract

Electrospun materials are able to mimic the native extracellular matrix of various tissues by comprising a network of polymer nanofibers with a high surface area providing a template with multiple binding sites to promote cellular functions and to restore damaged tissue. Self-powered piezoelectric (PE) implants show tremendous potential in regulation cellular activities in vitro and tissue repair in vivo. Poly(3-hydroxybutyrate) (PHB) has gained attention due to the natural origin, slow-rate biodegradation, and PE capacity; however, for successful practical application, PHB's low PE coefficient needs to be improved. Herein, we have fabricated electrospun PHB scaffolds with addition of homogeneously distributed crystals of piezoactive β-glycine (Gly) in concentrations of 5, 15, 20, and 30 wt%. Gly incorporation improves the fibers' nanotopography by the formation of cracks/pores on their surface. Based on X-ray photoelectron spectra, we suggest interactions on the PHB/Gly interfaces, including the formation of amide bonds, hydrogen bonding, and dipolar interactions. This provides an increase in the free surface energy and, consequently, in the wettability of the PHB-Gly composites compared to the neat PHB. Using piezoelectric force microscopy, we have obtained distributions of PE response in multiple points within the fibrous mats. We managed to achieve a 24-fold increase in the average PE coefficient for the PHB-Gly-30 scaffolds (from 0.1 to 3.0 pm/V). The described effects of β-Gly may promote cellular activity and tissue regrowth on the PHB-Gly scaffolds making this material promising for tissue engineering applications