Abstract
Ureteral balloon catheters and ureteral stents are implanted in large quantities on a daily basis. They are the suspected cause for about a quarter of all the nosocomial infections, which lead to approx. 20,000 deaths in Germany alone. To fight these infections, catheters should be made antibacterial. A technique for an antibacterial coating of catheters exhibiting an aspect ratio of up to 200 consists of a thin silver layer, which is deposited out of an aqueous solution, which is followed by a second step: chemical vapor deposition (CVD) of an organic polymeric film, which moderates the release rate of silver ions. The main concern of the second step is the longitudinal evenness of the film. For tubes with one opening as balloon catheters, this issue can be solved by applying a descendent temperature gradient from the opening to the end of the catheter. An alternative procedure can be applied to commercially available ureteral stents, which exhibit small drainage openings in their middle. The same CVD as before leads to a longitudinal homogeneity of about ±10%—at very low costs. This deposition can be modeled using viscous flow.
Highlights
Poly-p-xylylene (PPX), with its trivial name parylene, is an organic polymer that is used as a versatile coating material to protect sensitive, even very rugged, surfaces in hostile environments [1]
Because PPX belongs to the group of organic polymers which passed the approval of the FDA, it has been in use as a coating film on implantates for human beings for more than 40 years [4,5]
Ureteral balloon catheters and ureteral stents are used on a daily basis in large quantities
Summary
Poly-p-xylylene (PPX), with its trivial name parylene, is an organic polymer that is used as a versatile coating material to protect sensitive, even very rugged, surfaces in hostile environments [1]. High temperature leads to a low deposition rate and vice versa [15,16] Whereas this procedure has been successfully applied for balloon catheters, the ureteral stents offer an alternative possibility because they are delivered with a series of consecutive drainage openings and two openings at either end of the tube with a total length of 200 mm. The second step consists of depositing a film with and without additional holes between the two openings at either end, and the third step is modeling the resulting layer thicknesses If this method yields coatings which are sufficient for long-term control of silver release, this could cut the costs of the first method significantly because of the lower consumption of the precursor, which forms the coating, the higher deposition rates, resulting in a shorter deposition time, and much easier handling.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
