Dynamics of hematological parameters in rabbits for osteosubstitution by hydroxyapatite ceramics doped with germanium and in complex with blood coagulation activator

Abstract

Bone tissue has powerful regenerative properties, thanks to which, with stable fixation, quite large amounts of skeletal bone damage can be successfully repaired. However, in the case of fragmentary fractures, the use of osteosynthesis methods alone does not always ensure the optimal course of reparative regeneration, as its regenerative potential is lost. Therefore, there is a need to replace post-traumatic bone defects and stimulate reparative osteogenesis. For this purpose, doped or doped with various elements (Ge, Si, Zn, Ag, Cu) composite materials. The aim of the study was to investigate the dynamics of hematological parameters in rabbits for osteosubstitution by hydroxyapatite ceramics doped with germanium and in combination with a blood clotting activator. Model defects were formed in the radial diaphysis and femur metaphysis in rabbits with a 3 mm and 4.2 mm diameter drill bit, respectively. Anesthesia included acepromazine, thiopenate, and lidocaine infiltration anesthesia. Animals of the first experimental group (n = 12) were replaced by defects with granules of hydroxyapatite ceramics doped with germanium (HTGe), the second (n = 12) – hydroxyapatite ceramics doped with germanium with blood coagulation activator (HTGe + a), the third – (n = 12). hydroxyapatite α + β with active (α + β + a), and control – granules of undoped ceramics (HT). On day 7, animals of all groups had minor post-traumatic erythrocytopenia and oligochromemia. There was also a gradual increase in the content of leukocytes in the blood with a peak on the 14th day, which in the group HTGe + a lasted until the 30th day. The increase in the number of leukocytes and their peak values occurred within the physiological norm and only approached its upper limit. In most groups there was a pronounced thrombocytosis during the first 14 days with normalization to the 30th day, but in the 2nd experimental group the number of platelets returned to normal only on the 60th day. Changes in most integral hematological indices, which reflect the relationship between blood cell populations, are characteristic of the inflammatory-resorptive phase of reparative osteogenesis. The dynamics of hematological parameters indicates the absence of a pronounced reaction of the body to the implantation of hydroxyapatite composite doped with germanium. The combination of hydroxyapatite ceramics doped with germanium with coagulation activator eliminates post-traumatic oligochromemia and erythrocytopenia and significantly increases the level of hematological integral indices, which indicates a more intensive course of inflammatory-resorptive clinical resorptive aparation phase.