Comparison of Superhydrophilic, Liquid-Like, Liquid-Infused, and Superhydrophobic Surfaces in Preventing Catheter-Associated Urinary Tract Infection and Encrustation

Abstract

Over the past decade, superhydrophilic zwitterionic surfaces, slippery liquid-infused porous surfaces, covalently attached liquid-like surfaces, and superhydrophobic surfaces have emerged as the most promising strategies to prevent biofouling on biomedical devices. Despite working through different mechanisms, they have demonstrated superior efficacy in preventing the adhesion of biomolecules (e.g., proteins and bacteria) compared with conventional material surfaces. However, their potential in combating catheter-associated urinary tract infection (CAUTI) remains uncertain. In this research, we present the fabrication of these four coatings for urinary catheters and conduct a comparative assessment of their antifouling properties through a stepwise approach. Notably, the superhydrophilic zwitterionic coating demonstrated the highest antifouling activity, reducing 72.3% of fibrinogen deposition and over 75% of bacterial adhesion (Escherichia coli and Staphylococcus aureus) when compared with an uncoated polyvinyl chloride (PVC) surface. The zwitterionic coating also exhibited robust repellence against blood and improved surface lubricity, decreasing the dynamic coefficient of friction from 0.63 to 0.35 as compared with the PVC surface. Despite the fact that the superhydrophilic zwitterionic and hydrophobic liquid-like surfaces showed great promise in retarding crystalline biofilm formation in the presence of Proteus mirabilis, it is worth noting that their long-term antifouling efficacy may be compromised by the proliferation and migration of colonized bacteria as they are unable to kill them or inhibit their swarming. These findings underscore both the potential and limitations of these ultralow fouling materials as urinary catheter coatings for preventing CAUTI.

Keywords: biofilm; coating; encrustation; infection; migration; urinary catheter.

Figure 1

Typical top and cross-sectional SEM images of different surfaces (scale bars correspond to 10 and 50 μm, respectively).

Figure 2

(a) Chemical structures of PSBMA, LPB, SiO, and HC; (b) ATR–FTIR spectra (Me stands for CH3); (c) contact angle profiles of water and Fgn on different surfaces; (d) comparison of the water and Fgn CAHs on different surfaces; and (e) typical friction test curves: friction force versus displacement (n = 6, bars stand for the standard deviation of the mean; *p < 0.05 and **p < 0.01 compared with PVC).

Figure 3

(a) Amount of Fgn adsorbed on different surfaces after 2 h of coincubation and (b) typical fluorescent images of different surfaces after Fgn adsorption (n = 12, bars stand for the standard deviation of the mean, scale bars correspond to 100 μm; *p < 0.05 and **p < 0.01 compared with PVC).

Figure 4

(a) Typical images of different surfaces before and after contact with whole sheep blood for 30 s and (b) LDH relative activities of different surfaces after contact with whole sheep blood for 1 h (n = 6, bars stand for the standard deviation of the mean; *p < 0.05 and **p < 0.01 compared with PVC).

Figure 5

Quantitative counts of viable (a) E. coli and (b) S. aureus cells adhering to different surfaces after 24 h of static incubation; (c) the effect of surface energy on bacterial adhesion; quantitative counts of viable (d) E. coli and (e) S. aureus cells adhering to different surfaces after 24 and 72 h of dynamic incubation; (n = 6, bars stand for the standard deviation of the mean; *p < 0.05 and **p < 0.01 compared with PVC).

Figure 6

Representative fluorescent images of E. coli and S. aureus on different surfaces conditioned with neat and Fgn-supplemented PBS (scale bars correspond to 100 μm).

Figure 7

Comparison of biofilm formation on PSBMA, SiO, and LPB coatings conditioned with (a) pure PBS; (b) Fgn-supplemented PBS after 3 days; and (c) the corresponding three-dimensional images of the stained biofilm in image b (scale bars correspond to 100 μm).

Figure 8

Typical images of encrustation formation (a) on different surfaces and (b) in bacterial suspensions over time; (c) pH change with time; and (d) comparison of biofouling deposited on different surfaces over time.