Funding for this research was provided by:
Russian Science Foundation (17-75-30064, 19-74-00037)
Received: 2 March 2021
Accepted: 10 May 2021
First Online: 25 May 2021
: This work was supported by the Russian Science Foundation, projects №17-75-30064 (experiments with the PLA-gelatin mats) and №19-74-00037 (experiments with the PLA-BSA mats)<b>.</b>
: Ethical approval is not applicable, because this article does not contain any studies with human or animal subjects.
: Informed consent is not applicable.
: The authors declare no competing interests.