Methods for Regulation of Physicochemical and Biological Properties of the Surface of Poly(hydroxybutyrate-co-hydroxyvalerate) Film Specimens

Abstract

One of the main disadvantages of polymers widely used for the manufacture of implants, including prosthetic vascular grafts, as well as resorbable matrices for tissue engineering and regenerative medicine, is the hydrophobicity of their surface. The purpose of this work is to carry out comparative analysis of methods for surface modification of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) specimens aimed at regulating the hydrophilic, morphological, and biological properties of their surface. It was found that, when various hydrophilic compounds are incorporated into the volume of the polymer at a concentration of 10–50 wt %, the greatest hydrophilization of the surface of PHBV specimens is observed when using Pluronic^® F-68 at a concentration of 20 wt % (contact angle θ = 53 ± 9°). The treatment of specimens with 1 N NaOH for 6 h at 37°C made it possible to achieve a high degree of surface hydrophilization (θ = 36 ± 3°) with a concentration of negatively charged acid groups of 2.9 ± 0.1 nM/cm² and without visual signs of destruction. The incorporation of hydrophilic compounds into the volume of film specimens allows achieving significant hydrophilization of their surface but is poorly effective in terms of improving their matrix properties. Alkaline hydrolysis makes it possible to hydrophilize the surface of the specimen much more efficiently by generating a negative charge during treatment, which has a positive effect on the adhesion and proliferation of human adipose tissue-derived mesenchymal stromal cells.