Papain immobilized polyurethane as an ureteral stent material

Abstract

Long term use of polyurethane-based ureteral stent is hampered by the development of infection due to the formation of bacterial biofilm and salt deposition. Here papain, is covalently immobilized to polyurethane using glutarldehyde and is investigated as a possible anti-infective ureteral stent material. Fourier transform infrared spectrum confirmed its immobilization. Immobilized enzyme retained 85% of the activity of the free enzyme and about 12% loss of enzyme was observed from the polymer surface in one month. The modified polyurethane showed 8 log reduction in Staphylococcus aureus and 7 log reduction in Escherichia coli live colonies and 3-4 times decrease in the protein and carbohydrate in the biofilms than bare polymer. The amount of calcium and magnesium salts deposited on the polymer surface reduced by 40% after enzyme immobilization. 80% of L6 myoblast cells were viable on this material which indicated that it was noncytotoxic. A linear regression equation with hydrophilicity of the polymer surface and the cell surface hydrophobicity as the two independent variables was able to predict the number of live cells attached on the modified PU. This study indicated the possibility of using such an approach to overcome the problems of ureteral stent associated biofilm and salt encrustation.

Ureteral double‐J stents performances toward encrustation after long‐term indwelling in a dynamic in vitro model

“…The wetting behavior of the stents before and after insertion in the DIM for the different times was evaluated by measuring the WCA. Generally all the stents exhibited WCA values lower than 90°, hence witnessing their hydrophilic behavior, as previously observed for bare polyurethane . However, some small differences are visible from Figure .…”

“…Generally all the stents exhibited WCA values lower than 908, hence witnessing their hydrophilic behavior, as previously observed for bare polyurethane. 26 However, some small differences are visible from Figure 8. The PU-HY reference stent showed a starting hydrophilic behavior (WCA 5 82.58), as already reported in Figure 2.…”

Observations of Bacterial Biofilm on Ureteral Stent and Studies on the Distribution of Pathogenic Bacteria and Drug Resistance

“…The hydrophobicity on the surface of implants and the anti-adhesion surface embraced by heparin and phosphorylcholine are adjusted [35][36][37][38][39]. In addition, some scholars have continuously improved materials used for the ureteral stent to decrease the formation of bacterial biofilms [40][41][42]. However, the effect was unsatisfactory and defects occurred.…”

Preparation and Antifouling Property of Polyurethane Film Modified by PHMG and HA Using Layer-by-Layer Assembly

“…Polyurethane (PU) ureteral stents are wildly used in urological clinics for their good flexibility and elasticity, biocompatibility, and low cost compared to what or within which range of materials [ 1 , 2 ]. However, the hydrophobic surface of PU reduces the antifouling and antimicrobial properties, which results in the increasing amount of protein adsorption, bacteria adhesion, and salt deposition in a urine environment [ 3 , 4 ]. Thus, encrustation, infection, and implant-related post-complications such as ureteral stricture, perforation, and mucosal injury [ 5 , 6 ] are observed during the implantation in vivo.…”

“…Yuan et al [ 9 ] modified chondroitin sulfate onto the PU surface to improve its hydrophilicity and reduce the protein adsorption. Manohar et al [ 4 ] covalently crosslinked papain onto PU to prevent bacterial adhesion. Fischer et al [ 10 ] attached a hydrogel coating loaded with Ag nanoparticles to a PU conduit to improve its antibacterial activity.…”