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Vorträge und Posterpräsentationen (mit Tagungsband-Eintrag):

P. Steinbauer, A. Rohatschek, O.G. Andriotis, P.J. Thurner, R. Liska, S. Baudis:
"Adhesion Forces of selected Bone-binding Motifs determined via Single Molecule Force Spectroscopy";
Vortrag: Termis Eu 2019, Rhodes, Greece; 27.05.2019 - 31.05.2019; in: "Termis Eu 2019", (2019), S. 1248.



Kurzfassung englisch:
INTRODUCTION: An unmet clinical need of being able to glue small bone fractures with a
biocompatible, resorbable adhesive system is frequently stated [1]. Bone adhesives have to meet
several requirements for all day clinical use. Dental materials and primers influence the design of a
surgically realizable bone glue. The major problem in measuring the adhesion properties of a putative
bone adhesive primer is to distinguish between cohesive and adhesive forces. Our contribution
directly investigates adhesion processes at molecular level via single molecule force spectroscopy
(SMFS).
METHODS: A procedure to graft different adhesion motifs onto the tip of an AFM cantilever was
established similar to Wildling et al. [2] In SMFS experiments, the AFM tip works as a force sensor
with pN resolution. AFM chips were amino functionalized to attach a flexible PEG based linker
system. Thereafter, different adhesion motifs were clicked on these spacer and pull-off forces were
measured on hydroxyapatite (HAP) mimicking bone and on a TiO2 coated silicon wafer used as
implant surrogate. A specific amino acid sequence (AAS) with phosphorylated serines was chosen as
adhesion motif based on its suggested binding properties to HAP in statherin [3].
RESULTS & DISCUSSION: In order to validate tip functionalization and the experimental SMFS
procedure per se, the pull-off adhesion values of unfunctionalized, amino functionalized and linker
functionalized AFM tips were compared to the phosphorylated AAS sequence and the
unphosphorylated sequence on HAP and TiO2. The mean adhesion values of the phosphorylated AAS
were significantly higher. It was proven that phosphonic acid primers play a decisive role in adhering
on HAP and TiO2.
CONCLUSIONS: By the establishment of a procedure to functionalize an AFM tip with adhesion
motifs, it is possible to measure adhesion forces at molecular level on different substrates. The
phosphorylated AAS can indeed be considered as a fully biocompatible adhesion motif for a bone
glue. This is a substantial progress for designing bioadhesive systems.

Schlagworte:
Adhesion forces of selected bone-binding motifs, single molecule force spectroscopy, glue small bone fractures, biocompatible resorbable adhesive system, surgically realizable bone glue

Erstellt aus der Publikationsdatenbank der Technischen Universitšt Wien.