Hydrogel materials consisting of water-swollen polymer networks possess a large number of specific properties that render them attractive for a variety of biomedical applications. A particular class of these systems are responsive hydrogels that can change their swelling state due to changes of environmental parameters, like temperature or salt concentration. All this property renders these materials highly attractive for sensors, actuators, adhesives, and coatings. In this project new polymer systems are synthesized, which can be crosslinked by irradiation with light to form hydrogel materials with tailored properties. The photocrosslinking procedure allows full control over the crosslink density (via the irradiation time) and provides the means of patterning by masked irradiation (specifically of thin hydrogel films). The polymer network can further be modified by chemical reactions, for example, with biologically active ligands for specific binding of a target in biomedical use.
For the preparation of surface-attached hydrogel film (see scheme below) the substrate is first modified with an adhesion promoter, which is in our case also activated by light, and then a thin polymer film is deposited from solution onto the modified substrate. After drying the polymer layer is irradiated to introduce crosslinks and simultaneously form covalent bonds with the adhesion promoter to anchor the polymer network permanently to the substrate. Subsequent chemical modification is performed on the surface-attached networks according to the specific needs.
The properties and structure of such films is investigated in detail with spectroscopic and microscopic techniques (like surface plasmon resonance / optical waveguide spectroscopy or scanning force microscopy).
Internal FORTH collaborations:
- Prof. George Fytas and Dr. Benoit Loppinet (dynamic properties of hydrogel films, acoustic properties of colloidal crystals)
- Prof. Dimitris Vlassopoulos (rheological characterization of colloid monolayers and semifluorinated alkane monolayers)
- Dr. Alexandros Lappas (inorganic nanoparticle-hydrogel hybrids)
- Dr. Maria Farsari (2-photon hydrogel structuring)
- Dr. Stavros Pissadakis (optical fiber waveguide sensors)
- Dr. Emmanuel Stratakis (laser pulse interaction with hydrogels)
AIT, Vienna, Austria:
- Prof. Dr. Wolfgang Knoll (Surface Plasmon Spectroscopy)
- Dr. Jakub Dostalek (SPR/HOW Biosensors based on Hydrogels)
IMBB / FORTH and Department of Biology, University of Crete, Greece:
- Prof. Dr. Electra Gizeli (Acoustic Biosensors based on Hydrogels)
Deptartment of Materials Science and Technology, University of Crete, Greece:
- Prof. Dr. Maria Chatzinikolaidou (Cell Interaction with Hydrogel Layers)
Max Planck Institute for Polymer Research, Mainz, Germany:
- Dr. Renate Foerch (Plasma Modification of Polymer Surfaces)
University Medical Center of the Johannes Gutenberg University Mainz, Germany
- Dr. med. Lars Choritz (Hydrogel Implant Coating)
- Dr. Ulrike Ritz (Hydrogel-Osteoblast Interaction)