Development of a spheroid repair model based on nanosecond laser scalpel microsurgery

Abstract

Modern methods of cell spheroid laser microsurgery were used to develop a new simple and reproducible model for studying mechanisms of repair and regeneration in vitro. Nanosecond laser pulses (wave length 355 nm, frequency 100 Hz, pulse duration 2 ns) were used to perform microdissection of surface and inner zones of spheroids from human bone marrow multipotent mesenchymal stromal cells (BM MMSC). To provide preservation of spheroid viability after effective microdissection, the energy of laser impulses was regulated in the range 7—9 µJ. After microdissection the edges of wound surface for more than 180 degrees, the structure of spheroids was destructed. In a short period of time (2—3 hours), the cells surviving after injury changed their shape. Cells at the surface of spheroid and in the wound area became rounded. The complete restoration of spheroid structure took place over seven days due to remodeling of surviving cells.