Postdoctoral Fellow, Institute of Quantum Electronics, ETH-Zurich, 1996-99 Ph.D., Laboratory of Organic Chemistry, Swiss Federal Institute of Technology (ETH-Zurich), 1996 B.S. (1986), M.Sc. (1989), S. China University of Technology.His research involves organic synthesis, organic thin films, surface functionalization and nanochemistry. In addition to the fundamental studies, we also work with our collaborators to solve suitable and significant biological and biomedical problems.

     Surface biofunctionalization is to attach a thin layer of biologically active or inert molecules to a wide variety of materials, including nanoparticles for imaging or drug delivery, implantable biomaterials to enhance biocompatibility and drug delivery, and (implantable) biosensors. In this lecture, after briefly reviewing the work of our laboratory in this field, I will focus on the biofunctionalization of silicone catheters. One particular application is the prevention of Catheter associated urinary tract infection (CAUTI).

     Since biofouling and the subsequent pathogen colonization is eventually inevitable, a new strategy based on bacterial interference using non-pathogenic bacteria to guard against pathogens has attracted increasing interest. Crucial to the success of this strategy is to establish a high coverage and stable biofilm of non-pathogenic bacteria on the surface. The application of a non-pathogenic E. coli strain with type I fimbriae to interfere the colonization of uropathogenic bacteria on silicone, the common urinary catheter material.

    The resultant biofilms prevented the colonization of several strains of antibiotic-resistant uropathogenic isolates at a concentration thousand times higher than the diagnostic threshold for CAUTI. Binding of type I fimbriae with mannoside ligands on host is the first step for uropathogenic E. coli to colonize on the epithelium of the bladder and the lower urinary tract, leading to urinary tract infections. Our work indicated that the strong binding between surface mannoside and the fimH receptor at the tip of type I fimbriae promoted the production and secretion of partially acetylated polyglucosamine that is a well-known bacterial adhesin found in many bacterial biofilms.