Martin Kröger

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The molecular structure of the yeast nuclear pore complex (NPC) and the translocation of model particles have been studied with a molecular theory that accounts for the geometry of the pore and the sequence and anchoring position of the unfolded domains of the nucleoporin proteins (the FG-Nups), which control selective transport through the pore. The theory(More)
Poly (N-isopropylacrylamide) (PNIPAM) brushes and hydrogels serve as temperature-responsive cell culture substrates. The cells adhere at 37 °C and are detached by cooling to below the lower critical solution temperature T(LCST) ≈ 32 °C, an effect hitherto attributed to change in PNIPAM hydration. The article proposes a mechanism coupling the change of(More)
The properties of polymer layers end-grafted to the inner surface of nanopores connected to solvent reservoirs are studied theoretically as a function of solvent quality and pore geometry. Our systematic study reveals that nanoconfinement is affected by both pore radius and length and that the conformations of the polymer chains strongly depend on their(More)
The mechanical and physical properties of polymeric materials originate from the interplay of phenomena at different spatial and temporal scales. As such, it is necessary to adopt multiscale techniques when modeling polymeric materials in order to account for all important mechanisms. Over the past two decades, a number of different multiscale computational(More)
Thermoresponsive tissue culture substrates based on PNIPAM brushes are used to harvest confluent cell sheets for tissue engineering. The prospect of clinical use imposes the utilization of culture medium free of bovine serum, thus suggesting conjugation with adhesion peptides containing the RGD minimal recognition sequence. The optimum position of the RGD(More)
We extend to the three-dimensional situation a recent proof of hyperbolicity of the exact (to all orders in Knudsen number) linear hydrodynamics obtained from Grad's moment system [M. Colangeli, I. Karlin, M. Kröger, Phys. Rev. E 75, 051204 (2007)]. Proof of an H theorem is also presented.
We present an algorithm which returns a shortest path and related number of entanglements for a given configuration of a polymeric system in 2 or 3 dimensions. Rubinstein and Helfand, and later Everaers et al. introduced a concept to extract primitive paths for dense polymeric melts made of linear chains (a multiple disconnected multibead ‘path’), where(More)
Nanoparticles (NPs) are in use to efficiently deliver drug molecules into diseased cells. The surfaces of NPs are usually grafted with polyethylene glycol (PEG) polymers, during so-called PEGylation, to improve water solubility, avoid aggregation, and prevent opsonization during blood circulation. The interplay between grafting density σp and grafted PEG(More)
The flow behavior of polymeric liquids can be traced back to the complex conformational dynamics of polymer molecules in shear flow, which poses a major challenge to theory and experiment alike due to the inherently large number of degrees of freedom. Here we directly determine the configurational dynamics of individual actin filaments with varying lengths(More)