In vivo study on heparin/poly-L-lysine-copper coating for surface functionalization of ureteral stent

Polyurethane(PU)ureteral stents are used in clinics to maintain the ureteral patency.Due to biofilm formation and encrustation complications,long-term clinical usage has been limited.It is therefore necessary to develop an effective response to this unmet medical need.A heparin/poly-L-lysine/copper(NPs)coating was developed in our previous work that showed the effect of preventing infection and encrustation in vitro.In this work,a further study was conducted by grafting NPs on clinical ureteral stents that then were implanted into the infectious bladders of Wistar rats to investigate the effects of nanoparticles on bacterial growth and crystal deposition in vivo.It was found that decreased numbers of adherent microbes,urease amount splitting by bacteria,and deposited crystals were observed on the NPs stents with significant differences in comparison with PU stents.Besides,histological analysis showed that the NPs stents decreased the host tissue inflammation in close relation to the decrease biofilm formation and encrustation after 28 days of implantation.