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, A.B. Bussmann, M.G. Bauer and O. Lieleg, Oscillatory tribology performed with a commercial shear rheometer, Biotribology, (14) 11-18 (2018)

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)

T. Crouzier, K. Boettcher, A.R. Geonnotti, N.L. Kavanaugh, J.B. Hirsch, K. Ribbeck, and O. Lieleg, Modulating Mucin Hydration and Lubrication by Deglycosilation and Polyethylene Glycol Binding, Advanced Materials Interfaces, 2(18): 1500308 (2015)

(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:

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

C. Nowald, B. Käsdorf and O. Lieleg, Controlled nanoparticle release from a hydrogel by DNA-mediated particle disaggregation, Journal of Controlled Release, 246, 71-78 (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, 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)

L. Li, O. Lieleg, S. Jang, K. Ribbeck and J. Han, A Microfluidic In Vitro System for the Quantitative Study of the Stomach Mucus Barrier Function, Lab on a Chip, 12(20), 4071-4079 (2012)

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. 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)

M. Werb, C. Falcón García, N. Bach, S. Grumbein, S. Sieber, M. Opitz and O. Lieleg, Surface topology affects wetting behavior of Bacillus subtilis biofilms, 3:11 (2017)

S. Grumbein, M. Opitz, O. Lieleg, Selected metal ions protect Bacillus subtilis biofilms from erosion, Metallomics, 6(8) 1441-1450 (2014)

Sonderforschungsbereich SFB 863