Preparation Of Perfluoropolyether-functionalized Polyurethane For Catheter Surface Coating And Its Study On Antibacterial And Anti-adhesion Properties

Catheters are widely used in clinical treatment.However,patients are vulnerable to microbial infection during implantation,which has a negetivet impact on human health and causes economic burden.Antimicrobial coating of medical implants is a promising approach to resolve biofilm infection without significantly changing other properties of the implant matrix.In this paper,thermoplastic polyurethanes with allyl side chain(TPU-Ax)were designed and synthesized.The antibacterial substance of polylysine(TPU-Ax-PL)was obtained by grafting thiol polylysine(PL-SH)onto its side chain double bond,and its antibacterial properties was charactered.On this basis,we replaced partially soft segment Pluronic L-81 with double hydroxyl-terminated perfluoropolyether(E10H)to synthesize a range of polyurethane materials TPU-Fx,containing both main chain perfluoropolyether segment and side chain double bond.Then it was used as the coating agent to graft PL-SH onto polyurethane conduit.The catheter coating was obtained with dual functions of antibacterial and anti-adhesion.The details are as follows:Firstly,a series of thermoplastic polyurethanes with different contents of side chain double bonds,named TPU-Ax(x=0-5),were synthesized from Pluronic L-81,1,4-butanediol(BDO),3-allyloxy-1,2-propanediol and HMDI.After the film was made,the surface double bond and the prepared PL-SH were clicked specifically under ultraviolet light to construct the antibacterial polyurethane surface.The surface properties were characterized by XPS,GPC and other characterization methods.The results of antibacterial experiment showed that the antibacterial ability of the prepared antibacterial film was the strongest when the double bond content was 16 mol%or more,and the antibacterial rate of 10~7CFU/m L S.aureus and E.coli was more than98.7%in 10 min.Secondly,a series of polyurethanes with perfluorinated polyether segments in the main chain TPU-Fx(x=1-5)were synthesized by partially replacing Pluronic L-81with E10H.The polyurethane was used as the surface coating agent and coated on the surface of the polyurethane conduit.The hydrophobicity of the conduit surface was obviously improved,and the highest angle was up to 135°.The results of antibacterial experiments showed that the catheter TPU-Fx-PL coating had long antibacterial activity and anti-adhesion effect on E.coli and S.aureus,and the TPU-F2-PL coating,containing 8mol%E10H,had the strongest sustained antibacterial and anti-adhesion effect.Under the continuous action of bacterial urine containing 10~5CFU/m L E.coli,the bacteriostatic rate could be maintained at more than 99%within 7 days,and there was no bacterial adhesion on the catheter surface.