TY  - JOUR
A1  - Uhlig, Katja
A1  - Madaboosi, Narayanan
A1  - Schmidt, Stephan
A1  - Jäger, Magnus S.
A1  - Rose, Jürgen
A1  - Duschl, Claus
A1  - Volodkin, Dmitry V.
T1  - 3d localization and diffusion of proteins in polyelectrolyte multilayers
JF  - Soft matter
N2  - The interaction of diverse biomaterials with surfaces is more crucial than ever for biomedical applications to ensure efficiency and reproducibility. Very interesting surface materials are micrometer-thick polyelectrolyte multilayers. Not only their surface but also the bulk can be loaded with biomaterials like proteins or DNA for various purposes. Therefore, we established a method to analyze the lateral and vertical distribution of fluorescently labelled proteins of various size and charge in polyelectrolyte films composed of poly(L-lysine) and hyaluronic acid by confocal laser scanning microscopy. This approach enables us to measure the diffusion coefficients of the proteins via fluorescence recovery after photobleaching as a function of their vertical position in the film and facilitates the understanding of molecular interactions in the film with a high resolution in both space and time. As a result, we confirm that protein loading in the film is driven by electrostatic interactions - uncharged dextran molecules of 10 and 500 kDa do not diffuse into the film. Proteins of different sizes (3-11 nm) can diffuse relatively fast (D = 2-4 mm(2) s(-1)) independent of their net charge, indicating complex interpolymer interactions. This approach is a new powerful experimental tool to design the polyelectrolyte multilayers for bio-applications by finding a relationship between intermolecular interactions and mobility and availability of biomolecules to biological samples (e.g. cells) or detection units (e.g. biosensors).
Y1  - 2012
U6  - https://doi.org/10.1039/c2sm26500a
SN  - 1744-683X
VL  - 8
IS  - 47
SP  - 11786
EP  - 11789
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  -