ABSTRACT
An electrospark technology has been developed for obtaining a colloidal solution containing nanosized amorphous carbon. The advantages of the technology are its low cost and high performance. The colloidal solution of nanosized carbon is highly stable. The coatings on its basis are nanostructured. They are characterized by high adhesion and hydrophobicity. It was found that the propagation of microorganisms on nanosized carbon coatings is significantly hindered. At the same time, eukaryotic animal cells grow and develop on nanosized carbon coatings, as well as on the nitinol medical alloy. The use of a colloidal solution as available, cheap and non-toxic nanomaterial for the creation of antibacterial coatings to prevent biofilm formation seems to be very promising for modern medicine, pharmaceutical and food industries.
ABSTRACT
The novelty of the work lies in the creation and study of the physical and biological properties of biodegradable polymer coatings for stents based on poly(lactic-co-glycolic acid) (PLGA). Polymer coatings are capable of prolonged and directed release of molecules with a high molecular weight, in particular, protein molecules of prourokinase (m.w. 54 kDa). A technology has been developed to create coatings having a relative elongation of 40% to 165% and a tensile strength of 25-65 MPa. Coatings are biodegradable; the rate of degradation of the polymer in an isotonic solution varies in the range of 0.05%-1.0% per day. The created coatings are capable of controlled release of the protein of prourokinase, while about 90% of the molecules of prourokinase retain their enzymatic activity. The rate of release of prourokinase can vary from 0.01 to 0.08 mg/day/cm2. Coatings do not have a short-term toxic effect on mammalian cells. The mitotic index of cells growing on coatings is approximately 1.5%. When implanting the developed polymers in animals in the postoperative period, there are no complications. Histological examination did not reveal pathological processes. When implanting individual polymers 60 days after surgery, only traces of PLGA are detected. Thus, a biodegradable composite mechanically resistant polymer capable of prolonged release of the high molecular weight prourokinase enzyme has been developed.
