Biocompatible Nanomaterials

Research

Cells in 3D materials

Aerographite (AG) is a novel carbon-based material that exists as a self-supportive 3D network of interconnected hollow microtubules. It can be synthesized in a variety of architectures tailored by the growth conditions. The extracellular matrix (ECM) like micro interconnected porous structure of AG, makes it very promising material for tissue engineering. This similarity with a proper surface modification promotes bioengineering possibilities such as 3D cell proliferation and differentiation onto the AG substrate. We are also exploring cell adhesion in other 3D materials, such as NiTi and polyacrylamide.

C. Lamprecht, M. Taale, I. Paulowicz, H. Westerhaus, C. Grabosch, A. Schuchardt, M. Mecklenburg, M. Böttner, R. Lucius, K. Schulte, R. Adelung, C. Selhuber-Unkel (2016): A tunable scaffold of microtubular graphite for 3D cell growth.  ACS Applied Materials & Interfaces, 8:14980-14985. Link

K. Loger, A. Engel, J. Haupt, Q. Li, R. Lima de Miranda, E. Quandt, G. Lutter, C. Selhuber-Unkel (2016): Cell adhesion on NiTi thin film sputter deposited meshes. Materials Science and Engineering C, 59:611-616. Link

Y. Ganji, Q. Li, E. S. Quabius, M. Böttner, C. Selhuber-Unkel, M. Kasra (2016): Cardiomyocyte behavior on biodegradable polyurethane/gold nanocomposite scaffolds under electrical stimulation. Materials Science and Engineering C, 59: 10-18. Link

 

Cell adhesion and cellular forces

In the context of the ERC grant – CellInspired, a comprehensive understanding of cell adhesion regulation shall be established in order to create a basis for the development of novel biomimetic materials. The mechanical role of adhesion sites, which underlies medical and tissue engineering issues like cancer metastasis, wound healing and tissue formation, has only recently been accepted and opens new potentials for material research. 

Q. Li, S. Huth, D. Adam and C. Selhuber-Unkel (2016): Reinforcement of integrin-mediated T-Lymphocyte adhesion by TNF-induced Inside-out Signaling. Scientific Reports, 6:30452. Link

C. Herranz-Diez, Q. Li, C. Lamprecht, C. Mas-Moruno, S. Neubauer, H. Kessler, J. M. Manero, J. Guillem-Marti, C. Selhuber-Unkel (2015): Bioactive compounds immobilized on Ti and TiNbHf: AFM-based investigations of biofunctionalization efficiency and cell adhesion. Colloids and Surfaces B: Biointerfaces, 136:704-711. Link

L. F. Kadem, C. Lamprecht, J. Purtov, C. Selhuber-Unkel (2015): Controlled Self-Assembly of Hexagonal Nanoparticle Patterns on Nanotopographies. Langmuir, 31(34): 9261-9265. Link

 

Intracellular dynamics, cell migration and mechanosensing

Intracellular motion of endogenous particles is an essential mechanism for the biological function of cells. It is not only important for ensuring the transport of stored molecules, e.g., lipids and enzymes, but can also be a decisive factor for the development of diseases. Crowded systems are of particular interest, and a very specific biological system in which intracellular motion is related to pathogenicity is the human pathogenic amoeba Acanthamoeba castellanii. A. castellanii can, upon contact with the human eye, cause a severe keratitis after entering the eye through small lesions of the outermost epithelial cell layer. After having reached the cornea, these amoebae start to destroy target-cells by an extracellular killing mechanism that is based on the intracellular transport of granules towards the target cell. The granules release pore-forming molecules, which destroy the membrane of target cells. With our investigations we aim at understanding the biophysical principles underlying the “killing kiss” between Acanthamoeba and target-cells.

J. F. Reverey, J.-H. Jeon, H. Bao, M. Leippe, R. Metzler and C. Selhuber-Unkel (2015): Superdiffusion dominates intracellular particle motion in the supercrowded cytoplasm of pathogenic Acanthamoeba castellanii. Scientific Reports, 5: 11690.Link 

S. B. Gutekunst, C. Grabosch, A. Kovalev, S. N. Gorb and C. Selhuber-Unkel (2014): Influence of PDMS substrate stiffness on the adhesion of Acanthamoeba castellanii.  Beilstein Journal of Nanotechnology, 5: 1393-1398.  Link

 

Photoswitchable Biointerfaces

Cells are able to sense and actively react to the mechanical properties of their environment through a dynamic restructuring of adhesion sites. The ability of cells to adapt to environmental changes via modifying the cellular adhesion machinery implies that cell adhesion is a highly dynamic process. To study the mechanism of cellular mechanosensing, we have developed a novel and intriguing strategy for a reversible control of cell adhesion at the molecular level. This new approach is based on using c(RGDfK) ligands coupled to light-responsive azobenzene molecules. Using such biointerfaces, we are able to achieve a light-induced rapid, localized and reversible control of cell adhesion. 

L. F. Kadem, M. Holz, K. G. Suana, Q. Li, C. Lamprecht, R. Herges, C. Selhuber-Unkel (2016): Rapid Reversible Photoswitching of Integrin-mediated Adhesion at the Single-Cell Level. Advanced Materials, 28:1799-1802, DOI: 10.1002/adma.201504394. Link

 

Experimental methods used routinely in the lab

  • force microscopy: AFM, optical tweezers
  • light microscopy: fluorescence microscopy, spinning disk confocal microscopy, reflection interference contrast microscopy (RICM)
  • materials: diblock-copolymer micelle nanolithography, photolithography, hydrogels
  • cell culture

 

Funding

 

ERC

DAADZwei Studenten und eine Tasse Kaffee
SFB1261

 

 

                      

                  

    SFB 1261

 

 

 

Pictures from the lab

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