[Zurück]

S. Helfert, J. Hellmeier, E. Sevcsik, R. Liska, S. Baudis:
"Tailor-made biointerfaces on oxidic substrates via polymer brushes";
Vortrag: Termis Eu 2019, Rhodes, Greece; 27.05.2019 - 31.05.2019; in: "Termis EU 2019", (2019), S. 1338.

INTRODUCTION: The concept of building an interface between substrate surfaces and
biomolecules became very attractive for applications in the biomedical field. These interfaces can be
used for manufacturing of biosensing platforms, cell culturing [1] and tissue engineering [2]. Specific
surface engineering via synthetic polymer brushes can introduce a chemical environment that can
promote cell adhesion, proliferation, viability and enhanced extracellular matrix-secretion functions
[3].
METHODS: Flat silicon oxide substrates (e.g. glass, silicon wafer) were activated and aminofunctionalized
via chemical vapor deposition (CVD) of alkoxysilanes. Reversible addition-fragmentation
chain transfer (RAFT) polymerization was applied, to generate polymer brush interfaces
on these substrates. An activated ester RAFT reagent was bound to the amino-functionalized surface
and in a thermal- or light induced grafting-from polymerization, acrylamide polymer brushes were
generated. Aminolysis reactions were used to generate thiol end groups onto the brushes and these
were further coupled to maleimide (Mal) nitriloacetic acid (NTA) linkers for His-Tag coupling
reactions. The substrates were analyzed by water contact angle (WCA), ellipsometry and total internal
reflection fluorescence microscopy (TIRFM).
RESULTS & DISCUSSION: After CVD amino-functionalization, the generation of poly-Nacryloylmorpholine
(NAM) polymer brushes on flat silicon oxide substrates was accomplished via
thermal and light induced RAFT polymerization. WCA (wetting behavior) and ellipsometric layer
thickness analysis confirmed the presence of a polymer brush layer of approx. 20 nm. End group
modifi-cation by the use of aminolysis was confirmed by ellipsometry and resulting thiol groups were
labeled with Alexa 647-Mal to confirm their presence in TIRFM. Thiol end groups were linked to a
Mal-NTA spacer and coupled to an Alexa 555 labeled bovine serum albumin (BSA) molecules and
the bioconjugation was monitored via TIRFM.
CONCLUSIONS: Based on the collected data, it was possible to create a poly-NAM polymer brush
biointerface with BSA protein bioconjugated chain ends.

interface between substrate surfaces and biomolecules, biomedical field, surface engineering via synthetic polymer brushes, cell adhesion, proliferation, viability and enhanced extracellular matrix-secretion functions