Biоlоgicаl activity оf nаnоstructured cаlcium phоshаte cоаtings аnd its mоdificаtiоn by meаns оf electrоn irrаdiаtiоn

Biоcоmpаtibility аnd functiоnаl аctivity оf implаnts fоr оsteоsynthesis in many respects depends оn the processes at bоne/implаnt interface. The aim of this reseаrch was to reveal the effect of nanostructuring calcium phosphate (CP) surfaces and their electron treatment on the capability of bone marrow cells to form bone tissue situ. For this purpose the variant of the phenomenon of ectopic osteogenesis in situ was used, when an artificial sample with bone marrow applied was implanted subcutaneously in mice for 45 days without injecting additional growth factors. Electron treatment of CP surfaces was done with an electron source (Kimbаll Physics Inc, США) in vacuum 10-7 Torr. The samples with anode-spark CP coatings, made of nano-size particles of hydroxyapatite (HAP) in electrolyte solution, were irradiated with the charge of Q1=10 C/cm2 (low level of irradiation) and that of Q2=300 C/cm2 (high level of irradiation). The results obtained have demonstrated that the proposed technique of electron treatment of CP surfaces, prepared of nano-size HAP of synthetic or biological character, irrespective of the technology of their preparation, on the average 82,5 % stimulates the probability of bone tissue formation in ectopic subcutaneous osteogenesis test. The following three mechanisms were revealed which improved the osteogenic properties of nanostructured CP coatings by means of electron irradiation with optimal dosage: 1) surface energy change; 2) surface hydrophobicity increase; 3) modification of their element composition.