TY  - JOUR
A1  - Rossberg, Joana
A1  - Rottke, Falko O.
A1  - Schulz, Burkhard
A1  - Lendlein, Andreas
T1  - Enzymatic Degradation of Oligo(epsilon-caprolactone)s End-Capped with Phenylboronic Acid Derivatives at the Air-Water Interface
JF  - Macromolecular rapid communications
N2  - The influence of terminal functionalization of oligo(epsilon-caprolactone)s (OCL) with phenylboronic acid pinacol ester or phenylboronic acid on the enzymatic degradation behavior at the air-water interface is investigated by the Langmuir monolayer degradation technique. While the unsubstituted OCL immediately degrades after injection of the enzyme lipase from Pseudomonas cepacia, enzyme molecules are incorporated into the films based on end-capped OCL before degradation. This incorporation of enzymes does not inhibit or suppress the film degradation, but retards it significantly. A specific binding of lipase to the polymer monolayer allows studying the enzymatic activity of bound proteins and the influence on the degradation process. The functionalization of a macromolecule with phenyl boronic acid groups is an approach to investigate their interactions with diol-containing biomolecules like sugars and to monitor their specified impact on the enzymatic degradation behavior at the air-water interface.
Y1  - 2016
U6  - https://doi.org/10.1002/marc.201600471
SN  - 1022-1336
SN  - 1521-3927
VL  - 37
SP  - 1966
EP  - 1971
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Bhuvanesh, Thanga
A1  - Saretia, Shivam
A1  - Roch, Toralf
A1  - Schöne, Anne-Christin
A1  - Rottke, Falko O.
A1  - Kratz, Karl
A1  - Wang, Weiwei
A1  - Ma, Nan
A1  - Schulz, Burkhard
A1  - Lendlein, Andreas
T1  - Langmuir-Schaefer films of fibronectin as designed biointerfaces for culturing stem cells
JF  - Polymers for advanced technologies
N2  - Glycoproteins adsorbing on an implant upon contact with body fluids can affect the biological response in vitro and in vivo, depending on the type and conformation of the adsorbed biomacromolecules. However, this process is poorly characterized and so far not controllable. Here, protein monolayers of high molecular cohesion with defined density are transferred onto polymeric substrates by the Langmuir-Schaefer (LS) technique and were compared with solution deposition (SO) method. It is hypothesized that on polydimethylsiloxane (PDMS), a substrate with poor cell adhesion capacity, the fibronectin (FN) layers generated by the LS and SO methods will differ in their organization, subsequently facilitating differential stem cell adhesion behavior. Indeed, atomic force microscopy visualization and immunofluorescence images indicated that organization of the FN layer immobilized on PDMS was uniform and homogeneous. In contrast, FN deposited by SO method was rather heterogeneous with appearance of structures resembling protein aggregates. Human mesenchymal stem cells showed reduced absolute numbers of adherent cells, and the vinculin expression seemed to be higher and more homogenously distributed after seeding on PDMS equipped with FN by LS in comparison with PDMS equipped with FN by SO. These divergent responses could be attributed to differences in the availability of adhesion molecule ligands such as the Arg-Gly-Asp (RGD) peptide sequence presented at the interface. The LS method allows to control the protein layer characteristics, including the thickness and the protein orientation or conformation, which can be harnessed to direct stem cell responses to defined outcomes, including migration and differentiation. Copyright (c) 2016 John Wiley & Sons, Ltd.
KW  - Langmuir-Schaefer method
KW  - protein adsorption
KW  - stem cell adhesion
KW  - cell culture
KW  - fibronectin
Y1  - 2017
U6  - https://doi.org/10.1002/pat.3910
SN  - 1042-7147
SN  - 1099-1581
VL  - 28
SP  - 1305
EP  - 1311
PB  - Wiley
CY  - Hoboken
ER  -