Surface Functionalization of Ureteral Stents-Based Polyurethane: Engineering Antibacterial Coatings

Abstract

Bacterial colonization of polyurethane (PU) ureteral stents usually leads to severe and challenging clinical complications. As such, there is an increasing demand for an effective response to this unmet medical challenge. In this study, we offer a strategy based on the functionalization of PU stents with chitosan-fatty acid (CS-FA) derivatives to prevent bacterial colonization. Three different fatty acids (FAs), namely stearic acid (SA), oleic acid (OA), and linoleic acid (LinA), were successfully grafted onto chitosan (CS) polymeric chains. Afterwards, CS-FA derivatives-based solutions were coated on the surface of PU stents. The biological performance of the modified PU stents was evaluated against the L929 cell line, confirming negligible cytotoxicity of the developed coating formulations. The antibacterial potential of coated PU stents was also evaluated against several microorganisms. The obtained data indicate that the base material already presents an adequate performance against Staphylococcus aureus, which slightly improved with the coating. However, the performance of the PU stents against Gram-negative bacteria was markedly increased with the surface functionalization approach herein used. As a result, this study reveals the potential use of CS-FA derivatives for surface functionalization of ureteral PU stents and allows for conjecture on its successful application in other biomedical devices.

Recent development and future application of biodegradable ureteral stents

“…Despite Barros confirming through in vitro experiments that the stent could degrade within 14–60 days, with degradation rates controllable by altering the proportion of biodegradable materials, the in vivo degradation rate was excessively rapid (10 days), accompanied by a decline in mechanical performance during the degradation process ( Barros et al, 2015a ; Barros et al, 2016 ; Barros et al, 2018 ). Chitosan and silk fibroin have also been explored by other researchers as surface-degradable coatings for ureteral stents, facilitating drug delivery ( Ecevit et al, 2022 ; Soria et al, 2022 ).…”

“Functional upcycling” of polymer waste towards the design of new materials

“…405 Polymerisation on the PU surface has emerged as a common strategy for functional upcycling. 414–416…”

“…Furthermore, based on the examples of commercial PU functionalisation using polymers, we suggest that upcycled PU can be applied in active biomaterials with antifouling 406 or antibacterial (Table 6(2)) 415 properties by attaching active polymers or fatty acids (Fig. 15).…”

“…405 Polymerisation on the PU surface has emerged as a common strategy for functional upcycling. [414][415][416] The other covalent modification techniques are represented by the surface hydrolysis of the PU treated with a hydrochloric acid solution under reflux for 2 h (Fig. 14b).…”

“…14b and Table 6(2)). 415 Potentially, recycled polyols can be grafted to waste PU, providing functional materials from both waste components. 421 Chun reported a unique and promising upcycling approach in which recycled polyols from waste PU foams (prepared by thermal depolymerisation at 200 1C) were grafted onto PU to improve its properties, e.g., tensile strength, shape recovery, low-temperature flexibility, and water compatibility.…”