The results of surface modification of solvent casting films made from PHAs of various compositions are presented: homopolymer poly-3-hydroxybutyrate P(3HB) and copolymers comprising various combinations of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), 4-hydroxybutyrate (4HB), and 3-hydroxyhexanoate (3HHx) monomers treated with CO2 laser in continuous and quasi-pulsed radiation modes. The effects of PHAs film surface modification depending on the composition and ratio of monomers according to the results of the study of SEM and AFM, contact angles of wetting with water, adhesion and growth of fibroblasts were revealed for the laser radiation regime used. Under continuous irradiation with vector lines, melted regions in the form of grooves were formed on the surface of the films, in which most of the samples had increased values of the contact angle and a decrease in roughness. The quasi-pulse mode by the raster method caused the formation of holes without pronounced melted zones, the total area of which was lower by 20% compared to the area of melted grooves. The number of viable fibroblasts NIH 3T3 on the films after the qua-pulse mode was 1.5-2.0 times higher compared to the continuous mode, that is; and depended to a greater extent on the laser treatment mode than on the PHAs composition. The use of different modes of laser radiation and the presence of PHAs of various compositions makes it possible to influence the morphology and surface properties of polymer films in a targeted manner. Results obtained in the present study contribute to the solution of a critical issue of producing degradable polymer materials.

Conflicts of Interest:
The authors declare that they have no conflict of interest in the publication of this article. The authors have no conflict of interest to report in this work. Abstract was not submitted elsewhere and published here firstly

Funding:
The study was funded by State Assignment of the Ministry of Science and Higher Education of the Russian Federation (Project No. 0287-2021-0025)