Supporting Information
Small-Molecule-Hosting Nanocomposite Films with Multiple Bacteria-Triggered Responses
Svetlana Pavlukhina,† Iryna Zhuk, † Almagul Mentbayeva,‡ Emily Rautenberg,¶ Wei Chang,† Xiaojun Yu,† Betsy van de Belt-Gritter, ║ Henk J. Busscher,║ Henny C. van der Mei,║ and Svetlana A. Sukhishvili†*
† Department of Chemistry, Chemical Biology and Biomedical Engineering
Stevens Institute of Technology, Hoboken, NJ 07030, USA
‡ School of Engineering, Nazarbayev University, Astana 010000, Kazakhstan
¶Department of Computer Science & Department of Visual Arts and Technology,
Stevens Institute of Technology, Hoboken, NJ 07030, USA
║Department of Biomedical Engineering, University of Groningen and University Medical Center Groningen, 9700 AD Groningen, Netherlands
Figure S1. FTIR spectra of (MMT/PAA)n films with different number of deposited layers, n=50.5; 100.5; and 150.5.
Figure S2. Kinetics of (MMT/PAA)150.5 film swelling as a function of exposure time to solutions at various pHs (A), and time evolution of contact angle of a droplet of 0.01 M phosphate buffer solution at pH 7.5 on a (MMT/PAA)9.5-coated silicon wafer (B). In (A), films were deposited on a glass substrate and visualized using CLSM.
Figure S3. AFM images of (MMT/PAA)9.5 film before (A) and after gentamicin loading (B). In both cases, RMS roughness was 30±5 nm.
Figure S4. An SEM image of a (MMT/Gent)90.5 film deposited on a silicon wafer.
Figure S5. Ellipsometric thickness monitored during sequential adsorption of PAA and gentamicin on a BPEI-primed silicon wafer at pH 7.5.
Figure S6. pH-triggered release of gentamicin (determined by the ninhydrin method) from (MMT/PAA)3.5 films deposited on 4-μm-diameter silica particles (0.1% by weight solid content) exposed to 0.01 M phosphate buffer solutions of decreasing pH with 0.2 M NaCl . The initial amount of loaded gentamicin was 10 mg/m2.
Figure S7. Petrifilms antibacterial test results for bare silicon wafers, and silicon wafers containing (MMT/PAA)9.5 films with or without loaded gentamicin. Tests were performed with bacterial challenges of 1.6 x 105 and 1.6 x 107 bacteria/cm2 for E. coli ATCC 25922 and S. epidermidis ATCC 14990.
Figure S8. Representative live/dead images for HFOB 1.19 cell attachement and prolifiration on gentamicin-free and gentamicin-loaded (MMT/PAA)9.5 films, as well as on the surface of bare silicon wafers, indicating overwhelmingly higher number of live cells (green) as compared to dead cells (red). The scale bar is 100 µm.
Figure S9. An animation illustrating the suggested mechanism of the coating antibacterial action.