Our research deals with materials from the human body or such materials which are to be used for medical applications:

Biotribology and Biolubrication

We study the tribological properties of biological samples and biopolymer coatings. By exploiting loss and gain of function experiments, we aim to understand what molecular components are responsible for the outstanding mechanical properties of biolubricants and how they minimize friction and wear. One additional goal of this research part is to develop macromolecular coatings for medical applications.

Literature:
B. Winkeljann, P.-M. A. Leipold and O. Lieleg, Macromolecular coatings enhance the tribological performance of polymer-based lubricants, Advanced Materials Interfaces. doi.org/10.1002/admi.201900366 (2019)

M. Marczynski, B.N. Balzer, K. Jiang, T.M. Lutz, T. Crouzier, and O. Lieleg, Charged glycan residues critically contribute to the adsorption and lubricity of mucins, Colloids and Surfaces B: Biointerfaces, doi.org/10.1016/j.colsurfb.2019.110614 (2019)

B. Winkeljann, K. Boettcher, B. Balzer and O. Lieleg, Mucin coatings prevent tissue damage at the cornea-contact lens-interface, Advanced Materials Interfaces, (4) 19, 1700186 (2017)

EU Horizons 2020 Project APRICOT "Anatomically Precise Revolutionary Implant for bone Conserving Osteoarthritis Treatment"

(Bio-)Hybrid-Materials

Many biomolecules offer outstanding properties but cannot be used in medical/technical applications on their own. Thus, we develop hybrid materials where we either mix biological molecules in new combinations or add biological components to inorganic/synthetic materials. Examples for such hybrid-materials are hydrogels with programmable drug release kinetics and thermally induced auto-gelation behavior and a bio-hybrid mortar that obtained water-repellent properties by the addition of a biological substance.

 

Literature:
C. Kimna and O. Lieleg, Engineering an orchestrated release avalanche from hydrogels using DNA-nanotechnology, Journal of Controlled Release. 304, 19-28 (2019)

B. Winkeljann, B. Käsdorf, J. Boekhoven and O. Lieleg, Macromolecular coating enables tunable selectivity in a porous PDMS matrix, Macromolecular Bioscience, 1700311 (2017)

S. Grumbein, D. Minev, M. Tallawi, K. Boettcher, F. Prade, F. Pfeiffer, C.U. Große and O. Lieleg, Hydrophobic Properties of Biofilm-Enriched Hybrid Mortar, Advanced Materials, 28(37): 8138-8143 (2016)

TV report Nano (3Sat) 5:21 Min.

Microfluidic chips for diffusion studies

PDMS microchips are a versatile platform to study the behavior of fluids on small dimensions. We aim at generating microchip solutions to quantify diffusive processes at the liquid/gel interface and to understand the physico-chemical principles governing the penetration behavior of molecules and nanoparticles into hydrogels. In collaboration with medical researchers and physicists, we then compare the results obtained from our gel-on-chip assays to in vivo data and theoretical models.

Literature:
M. Marczynski, C. Rickert, S. Semerdzhiev, W. van Dijk, I. Segers-Nolten, M.M.A.E. Claessens, and O. Lieleg, α-Synuclein penetrates mucin hydrogels despite its mucoadhesive properties, Biomacromolecules, DOI:  10.1021/acs.biomac.9b00905 (2019)

M. Marczynski, B.T. Käsdorf, B. Altaner, A. Wenzler, U. Gerland, and O. Lieleg, Transient binding promotes molecule penetration into mucin hydrogels by enhancing molecular partitioning, Biomaterials Science. 6, 3373 - 3387 (2018)

F. Arends, S. Sellner, Ph. Seifert, U. Gerland, M. Rehberg, and O. Lieleg, A microfluidics approach to study the accumulation of molecules at basal lamina interfaces, Lab on a Chip, 15: 3326 – 3334 (2015)

Material properties of bacterial biofilms

Bacteria secrete a broad range of biopolymers, that form a protective matrix around the prokaryotes. This community of biopolymers and bacteria is referred to as a biofilm. Bacterial biofilms can grow on a broad variety of surfaces and constitute a severe issue in industry and medicine. We aim at quantifying the mechanical and water-repellent properties of bacterial biofilms. We are also interested how different chemical environments affect those material properties. By doing so, we hope to develop new strategies for the removal of biofilms from surfaces.

Literature:
C. Falcón García, M. Kretschmer, C. Lozano-Andrade, M. Schönleitner, A. Dragoš, Á.T. Kovács, and O. Lieleg. Metal ions weaken the hydrophobicity and antibiotic resistance of Bacillus subtilis NCIB 3610 biofilms, NPJ Biofilms and Microbiomes, DOI : 10.1038/s41522-019-0111-8 (2019)

E. N. Hayta and O. Lieleg, Biopolymer-enriched B. subtilis NCIB biofilms exhibit increased erosion resistance, Biomaterials Science, 7, 4675 - 4686 (2019)

C. Falcon Garcia, F. Stangl, A. Götz, W. Zhao, S. Sieber, M. Opitz, and O. Lieleg, Topographical alterations render bacterial biofilms susceptible to chemical and mechanical stress, Biomaterials Science. 7, 220 – 232 (2019)

Sonderforschungsbereich SFB 863