[ANGIOGENESIS IN THE TISSUES AFTER THE INJECTION OF STROMAL STEM CELLS OF BONE MARROW ORIGIN CLOSE TO THROMBOSED VEIN IN AN EXPERIMENT].

The effects of the injection of autologous multipotent stromal stem cells of bone marrow origin (MSSCBM) (mesenchymal stem cells) with green fluorescent protein gene, additionally marked with DAPI nuclear stain, close to a thrombosed hindlimb vein, were studied by fluorescent microscopy in adult male Wag rats (n = 214). The control groups consisted of intact rats (n = 12), animals with venous thrombosis without the injection of MSSCBM (n = 71) and rats that received paravasal injection of MSSCBM, but without preliminary modeling of venous thrombosis (n = 72). It was found that MSSCBM participated in the development of granulation tissue at the site of surgical intervention performed during the modeling of thrombosis. The rapid development of granulation tissue at the site of surgical trauma may contribute to faster wound clearance from detritus, nonviable tissue and antigenic substances, early onset of tissue repair processes and rapid healing. Restoration of blood flow in the tissue region of a thrombosed vein began later than after the intravenous injection of MSSCBM.

Reaction of the rat tissues to implantation of polyhydroxyalkanoate films and ultrafine fibers.

The reaction of various tissues of rats to implantation of polyhydroxyalkanoate films and ultrafine fibers was studied by optic microscopy. Implantation of polyhydroxyalkanoate films into the abdominal cavity caused a peritoneal reaction, leading after 1 month to the formation of fibrous adhesions between polyhydroxyalkanoate and intestinal loops. Under the skin and in the muscle tissue polyhydroxyalkanoate films were encapsulated in a thick fibrous capsule. Implantation of polyhydroxyalkanoate ultrathin fibers led to formation of foreign body granulomas in all tissues with perifocal inflammation and sclerosis of the adjacent tissues. The polymer was fragmented in these granulomas and phagocytosed by macrophages with the formation of giant foreign body cells. Hence, polyhydroxyalkanoate materials implanted in vivo caused chronic granulomatous inflammatory reaction and were very slowly destroyed by macrophages.