Please select the desired project time frame:

• July 2026
• January 2026
• July 2025
• January 2025
• July 2024
• January 2024
• July 2023
• January 2023
• July 2022
• January 2022
• July 2021
• January 2021
• July 2020
• January 2020
• July 2019
• January 2019
• July 2018
• January 2018
• July 2017
• January 2017
• July 2016
• January 2016
• July 2015
• January 2015
• July 2014
• January 2014
• July 2013
• January 2013
• July 2012
• January 2012
• July 2011
• January 2011
• July 2010
• January 2010
• July 2009
• January 2009
• July 2008
• January 2008
• July 2007
• January 2007
• July 2006
• January 2006
• July 2005
• January 2005
• July 2004
• January 2004
• July 2003
• January 2003
• July 2002
• January 2002
• July 2001
• January 2001

Start of funding 01.01.2017

Antimicrobial Coatings Inspired by Spider Silk and Mussel Proteins

---

Coatings can be a resource-efficient approach towards preventing infectious disease without encouraging drug resistance due to their ability to passively resist bacterial colonization. In this project, we aim to produce robust coatings based on recombinant spider silk proteins (spidroins) anchored to polymeric and metallic substrates by mussel-inspired adhesive molecules. Specifically, films made of recombinant spidroins derived from Araneus diadematus dragline silk, which do not support mammalian cell adhesion and show bacteriostatic behavior, will be conjugated to molecules containing 3,4-dihydroxyphenylalanine (DOPA) which can associate strongly with a variety of surfaces. Additionally, since many biomedical applications benefit from responsiveness towards environmental cues, the second aim is to create a pH-switchable antimicrobial surface. Therefore, DOPA anchoring molecules will also be conjugated to the N-terminal domain of spidroins of Latrodectus hesperus, resulting in surfaces with switchable properties resulting from the pH-sensitive dimerization of this domain.

Final report:
Based on the spider silk protein eADF4(C16), surface coatings were developed within the framework of the cooperation. The spider silk proteins form supramolecular structures upon addition of phosphate ions in aqueous buffers, which adsorb as 2-30 nm thick layers on the surface. Regardless of the substrate (hydrophobic, hydrophilic, organic and inorganic), coatings could be formed without surface activation. Since eADF4(C16) self-assembles to a stable, hydrogel-like network by forming ß-sheet crystals acting as a robust layer, the previously planned functionalization with DOPA-modified peptides was not necessary. The surfaces were characterized by AFM, SEM and GIWAXS.

Moreover, the antimicrobial behavior of the layer was tested. After incubation for 24 hours at 37°C the bacterial growth was reduced up to 99% on the surfaces, for both gram-negative (Escherichia coli) and gram-positive (Staphylococcus epidermidis) bacteria. Dead bacteria were not observed, suggesting a bacteriostatic but not a bactericidal mechanism.

Due to the mild assembly conditions in aqueous solution without the use of chemical cross linkers and the antimicrobial effect, potential applications towards biomedical surface functionalization are possible. The gained results have already been published (Ref. 1).

The travel expenses paid by BaCaTeC enabled the direct scientific exchange on protein and surface modification. In the future, the working groups will stay in contact for further collaboration.

Publications:
(1) Zha, R. H., Delparastan, P., Fink, T. D., Bauer, J., Scheibel, T. & Messersmith, P. B. (2019). Universal nanothin silk coatings via controlled spidroin self-assembly. Biomaterials science, 7(2), 683-695.