In Vitro Biofilm Models for Device-Related Infections Matthias T. Buhmann, Philipp Stiefel, Katharina Maniura-Weber, Qun Ren  Trends in Biotechnology  Volume 34, Issue 12, Pages 945-948 (December 2016) DOI: 10.1016/j.tibtech.2016.05.016 Copyright © 2016 Elsevier Ltd Terms and Conditions

Figure 1 Schematic Illustration of a Ureteral Stent in the Urinary Tract Environment. This environment includes the abiotic material (red), biotic surfaces (orange), environmental conditions (blue), and microbiota (green). The biological surface is composed of epithelial cells, which secret host defense factors (A). To protect the abiotic surface against colonization, either anti-adhesive (B) or biocidal (C) modifications can be introduced. Conditioning film formation can change the release profile of antimicrobials and, together with dead cells, can reduce/abolish the functionality of active coatings (D). Furthermore, the successful prevention of surface colonization is highly dependent on microbial surface properties (E), which are affected by their environmental conditions (F). Bacterial cells in biofilms are embedded in a self-produced EPS matrix that impedes penetration of the antimicrobials (G). Key: , glycosaminoglycan (GAG); , live bacterial cells; , dead bacterial cells; , extracellular polymeric substances (EPS); , antimicrobial peptides; , antimicrobials; , conditioning film. Trends in Biotechnology 2016 34, 945-948DOI: (10.1016/j.tibtech.2016.05.016) Copyright © 2016 Elsevier Ltd Terms and Conditions

Figure 2 Schematic Illustration of the Important Factors To Be Considered in an In Vitro Model. These factors include the abiotic material (red), growth conditions (blue), microbiota (green), and biological surfaces (orange). Various important characteristics and parameters for the in vitro model are listed which should be adjusted to simulate the in vivo situation. In addition, examples of crucial factors are mentioned that should be considered when choosing the in vitro settings. Trends in Biotechnology 2016 34, 945-948DOI: (10.1016/j.tibtech.2016.05.016) Copyright © 2016 Elsevier Ltd Terms and Conditions