[Mathematical modeling of stress in plasma coatings used in medicine].

logical or synthetic materials provide the most effective biological compatibility. Such scaffolds can be filled with stem cells, growth factors, blood plasma proteins, and other active substances including drugs [1 5]. In spite of adequate biological compatibility, such implants cannot be used in organs and tissues subjected to serious stress during functioning (e.g. teeth and joints). This problem can be solved using application of porous scaffold coat ings to metal implants. These scaffold coatings are based on hydroxyapatite, tricalcium phosphate, and other bio logically compatible materials. Porous coating structure provides for the accumula tion of various substances. The coating should include macropores and capillary pores (nanopores) (Fig. 1). A coating modified with pores serves as a container for long term storage of liquids, whereas capillary pores pro vide transport of the liquids. The liquid can contain drugs or other active sub stances migrating to the pathological focus. Therefore, coating of implants with layers of the required structure is an important problem. However, increase in coating porosity reduces its strength. The technology of implant coating should provide the necessary balance between coating porosity and coating strength. Plasma coating of powdered materials is a promising approach to coating with porous layers [6]. Control of coating strength is an important component of the coat ing technology. The coating strength should not exceed a limiting threshold: