Synthesis and structure of antibacterial coatings formed by electron-beam dispersion of polyvinyl chloride in vacuum

A new antibacterial coating has been synthesized to modify implants with prolonged release of a medicinal antibacterial component (ciprofloxacin). Condensed in vacuum, the products of electron beam dispersion of PVC were used as one of the components of the target. It is shown that the repeated action of the electron flow on condensed destruction products of PVC is accompanied by the formation of poly-conjugated structures devoid of chlorine. Thermal treatment of the hydrocarbon layer (500 °C) leads to the formation of graphite-like structures and polyene fragments up to 8 units in length. The antibacterial coating (PVC2-ciprofloxacin) is formed by the action of a low-energy electron flow on a mechanical mixture of ciprofloxacin and condensed PVC destruction products. It is shown that in comparison with the antibacterial layer PU - ciprofloxacin, the proposed coating is characterized by a higher resistance to abrasion. The PU - ciprofloxacin layer is completely worn out after 17 cycles. The worn-out areas of the proposed coating after 17 and 25 wear cycles are 47% and 53% respectively. Heat treatment of the coating, including standard sterilization, does not affect the kinetics of the release of ciprofloxacin from the hydrocarbon matrix. Unlike the PU layer - ciprofloxacin, the prolonged release (sustained release) of ciprofloxacin in PVC2-ciprofloxacin is not ensured by intermolecular interaction but by the mechanical containment (confinement) of ciprofloxacin using a hydrocarbon matrix. Microbiological studies showed high antibacterial activity of the proposed composite layer in relation to P. aeruginosa and E. coli. The activity was maintained after abrasive coating treatment for 24 h.