Funding: the study was performed within the framework of the state assignment of the Ministry of Science and Higher Education of the Russian Federation (agreement № 075-03-2022-107, project № 0714-2020-0006). The study involved the use of equipment of the Semenov Federal Research Center for Chemical Physics RAS.

Author contribution: Pekov SI — concept, data analysis, manuscript writing; Bocharov KV — experimental procedure, resource provision; Bormotov DS — experimental procedure, data analysis; Eliferov VA — experimental procedure, communication with surgeons; Parochkina EV — experimental procedure; Sorokin AA — data analysis, concept; Nikolaev EN — resource provision; Popov IA — search of funding sources, research management.

Compliance with ethical standards: the study was approved by the Ethics Committee of the Burdenko Research Institute of Neurosurgery (protocols № 40 dated 12 April 2016 and № 131 dated 17 July 2018) and conducted in accordance with the principles of the Declaration of Helsinki (2000) and its subsequent revisions. All patients submitted the informed consent to study participation and the use of biomaterial for scientific purposes.