SiO2 nanosphere coated tough catheter with superhydrophobic surface for improving the antibacteria and hemocompatibility

Abstract

Catheter infection is the most common complication after vascular catheter placement, which seriously threatens the survival of critically ill patients. Although catheters with antibacterial drug coatings have been used, catheter infections have not been effectively resolved. In this research, a SiO₂ nanosphere-coated PTFE catheter (PTFE-SiO₂) with enhanced antibacterial and excellent mechanical properties was prepared via dopamine as a graft bridge. The microscopic morphology results show that the nanospheres are uniformly dispersed on the surface of the catheter. The physicochemical characterization confirmed that PTFE-SiO₂ had reliable bending resistance properties, superhydrophobicity, and cytocompatibility and could inhibit thrombosis. Antibacterial results revealed that PTFE-SiO₂ could hinder the reproduction of E. coli and S. aureus. This research demonstrates the hydroxyl-rich materials obtained by hydroboration oxidation have the advantages of better dispersion of functional coatings, indicating their potential for helpful modification of catheters.

Keywords: SiO2 nanosphere; antibacterial; blood compatibility; catheter; superhydrophobic.

FIGURE 1

(A) The digital photos of commerical catheter, PTFE catheter, and PTFE-SiO₂ catheter, respectively; (B) FTIR spectra of commerical catheter, PTFE catheter, and PTFE-SiO₂ catheter, respectively; (C) and (D) Water contact angle of the lumen surface of the inner surfaces of PTFE catheter, and PTFE-SiO₂ catheter at the 5 s time point, respectively.

FIGURE 2

The suefaces SEM images of commerical catheter, PTFE catheter, and PTFE-SiO₂ catheter, respectively.

FIGURE 3

(A) Maximum compressive force and (B) compressive modulus after 1000 cycle compressive fatigue tests; (C) Images of three-point bending tests; (D) Typical the first and one thousandth loading-unloading compression cycle curves of commerical catheter, PTFE catheter, and PTFE-SiO₂ catheter.

FIGURE 4

CCK-8 assay of (A) the adhesion viability after 24 h culture and (B) proliferation viability after 1, 3, and 5 days culture of HUVECs onto cover slips, commerical catheter, PTFE catheter, and PTFE-SiO₂ catheter, respectively; (C) Quantitative number measurements of L929 cells on the inner surfaces of cover slips, commerical catheter, PTFE catheter, and PTFE-SiO₂ catheter after culturing for 3 days; (D) Live/dead staining viability assay of L929 cells cultured on the inner surfaces of cover slips, commerical catheter, PTFE catheter, and PTFE-SiO₂ catheter after culturing for 3 days.

FIGURE 5

(A) Whole blood clotting time (B) Plasma recalcification time; (C) Quantification of relative hemolysis rate; (D) Platelet deposition determined by lactate dehydrogenase assay. (For plasma recalcification time test, TCPs exposed to PPP with and without CaCl₂ were used as positive control and negative control, respectively; For hemolysis test, water and 0.9% normal saline (NS) serve as positive and negative groups, respectively; n = 5, *p < 0.05, **p < 0.01).

FIGURE 6

(A) Visual images of the antibacterial zone of catheter to Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) after incubation for 6 h. Spot ①, ②, and ③ represents commerical catheter, PTFE catheter, and PTFE-SiO₂ catheter, respectively; of commerical catheter, PTFE catheter, and PTFE-SiO₂ catheter, respectively; (B) and (C) Quantified antibacterial zone of commerical catheter, PTFE catheter, and PTFE-SiO₂ catheter after 6 h incubation with E. coli and S. aureus, respectively. (n = 5, **p < 0.01)

FIGURE 7

Quantitative analysis of the antibacterial properties of catheter: (A) Conoly-counting assay of catheter against E. coli and S. aureus; (B) Antibacterial rate of catheter after 6 h incubation with E. coli and S. aureus (quantitative analysis of colony statistics); (C) Quantitative analysis of photometric method after 6 h incubation with E. coli and S. aureus. (n = 5, *p < 0.05, **p < 0.01)

FIGURE 8

SEM images of S. aureus on the surfaces of commerical catheter, PTFE catheter, and PTFE-SiO₂ catheter, respectively. (Yellow solid represent bacteria in biofilm).