Incorporation of silver nanoparticles by the irradiation process in central venous catheter (CVC) of polyurethane coated with titanium oxide for antimicrobial activity

Intravascular catheters are indispensable allies in the practice of modern medicine, particularly in intensive care units (ICUs). Central Venous Catheter (CVC) patients who are hospitalized for a long time receive medication and feeding, however, being an important source of infection of the primary bloodstream. Polyurethane CVCs may have their surface modified by the incorporation of titanium and silver (Ti/Ag) which have antimicrobial characteristics known from antiquity. The incorporation of the silver nanoparticles on the polymer can be done with the use of ionizing radiation, which will also sterilize the material. Thus, this work aims to use ionizing radiation to incorporate silver nanoparticles in Central Venous Catheter (CVC) in order to acquire antibacterial properties. For this purpose CVC Pellethane 2363-65D, thermoplastic elastomer polyurethane (TPU), pure titanium oxide, synthesized by the sol-gel process and silver nanoparticles (NpAg₉25) were used. Irradiation for incorporation of silver was at a dose of 25 kGy and at a dose rate of 1.03 kGy/h in a Gammacell 220 irradiator of ⁶⁰Co. Subsequently, the catheters were sterilized at a dose of 25 kGy. It can be concluded that the incorporation of silver by the irradiation process was possible and that this process does not affect the structure of the polymer, which is important for the correct insertion of the central venous catheter into the patient's body. It was observed that the sol-gel method, for deposition of the titanium on the surface of the CVC, was not homogeneous, making difficult the incorporation of the silver that depends on the titanium in this process. The antimicrobial analysis tests did not indicate antimicrobial activity in catheters coated with titanium and silver, it is believed that the chosen methodology is inadequate for the type of analysis. (author)