Category: New Technology: Miscellaneous

MP22-10 - Effect of Highly-Aligned Nanoscale Surface Structures on Microbial Adhesion

Sat, Sep 22
2:00 PM - 4:00 PM

Introduction & Objective :

Catheter-associated urinary tract infection (CAUTI) is one of the most common care-associated infections around the world. The catheter surface is an ideal milieu for microbial attachment and biofilm formation. Bacterial attachment depends not only on the chemical properties of the catether material but also on the size, shape and spacing of the micro/nano-scale topographical features on the surface of catheters. Changing the topography of the surface using well-defined periodic nanoscale surface features is a novel method to prevent biofilm formation.To investigate the role of aligned nanofiber-coating on retention of the most common fungal and bacteria uropathogenic organism, Candida albicans and Escherichia coli.

Methods :

Spinneret-based tunable engineered parameters (STEP) technique was used to deposit highly aligned polystyrene fibers of uniform diameter and spacing. Surface architectures were varied by changing nanofiber diameter and spacing on flat polystyrene substrata and on the surface of latex, polyurethane, and silicone catheters. Dynamic retention assays were carried out and microbial attachment density on engineered surfaces was compared to the unmodified polystyrene surfaces, using colony counting, fluorescent microscopy, and image processing. Short-term and long-term effects of the introduction of an anti-adhesion biocompatible chemical coating were also studied. 

Results :

The fiber diameters were divided into three different groups (Dfiber/Dcell = 0.12−0.24, 0.24−0.36, and 0.36−0.48), and the normalized cell attachment densities were averaged in each group. Figure 1 depicts the difference in the average normalized cell attachment of C. albicans density for the three groups, which is statistically significant.

Fluorescent microscopy images (Figure 2) of coated and uncoated stents showed the extent of cell attachment of E.coli  density on the unmodified surface, and 0.3 µm fiber-coated surface (Dfiber/Dcell = 3.3). On the other hand, coating stents with Pluronic F108 resulted in significant decrease in cell attachment of E.coli density.

Conclusions :

Our experiment showed that the surface texture that reduces ­C. albicans attachment by as much as 70% has no effect on Uropathogenic E. coli (UPEC) attachment. Pluronic coating decreases bacterial attachment by 80%. 

Yiying Wang

Graduate Student
Virginia Tech
Blacksburg, Virginia

Mohammed Shahait

Division of Urology, University of Pennsylvania
Philadelphia, Pennsylvania

Advanced Robotic Urology, University of Pennsylvania.
Interested in outcome research, new imaging modalities

Carolyn Mottley

Blacksburg, Virginia

Zhou Ye

Blacksburg, Virginia

Amrinder Nain

Blacksburg, Virginia

Timothy Averch

Chief, Division of Urology
Palmetto Health - University of South Carolina
University of South Carolina
Columbia, South Carolina

Bahareh Behkam

Blacksburg, Virginia