Microfabrication of 3D-hydrogels via two-photon polymerization of poly(2-ethyl-2-oxazoline) diacrylates. (5th January 2020)

• Record Type: Journal Article
• Authors: Wloka, Thomas; Czich, Steffen; Kleinsteuber, Maximilian; Moek, Elisabeth; Weber, Christine; Gottschaldt, Michael; Liefeith, Klaus; Schubert, Ulrich S.
• Is Part Of: European polymer journal. Volume 122(2020)
• Publication Date: 2020-01-05
• Subjects: Two-photon polymerization -- Hydrogel -- Poly(2-oxazoline) -- Tissue engineering; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2019.109295
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: Highlights: The novel water-soluble photoinitiator BTABcP-1 is a suitable photoinitiator for two-photon polymerization (2PP). Bisacrylate functional poly(2-ethyl-2-oxazoline) macromonomers were directly polymerized by 2PP. The processability and structural accuracy of the hydrogels were enhanced in comparison to similar PEG based telechelics. Abstract: Bis(acrylate) functionalized poly(2-ethyl-2-oxazoline)s (PEtOx-DA) served as macromonomers as well as crosslinkers for the structured two-photon polymerization (2PP) using a novel water soluble photoinitiator (PI). The telechelics were obtained via end capping of the trans -1, 4-dibromo-but-2-ene (DBB) initiated cationic ring-opening polymerization (CROP) of 2-ethyl-2-oxazoline. Analysis of the PEtOx-DA by means of mass spectrometry, nuclear magnetic resonance spectroscopy and size exclusion chromatography revealed that the CROP in refluxing acetonitrile was successfully scaled-up from 10 g to 200 g for degrees of polymerization of 10 and 18, respectively. The PI based on a cyclopentanone dibenzylidene based donor-acceptor-donor π system coupled to an acrylate functionalized triaryl amine proved suitable to produce structured hydrogels. Fabricated voxel arrays with different shot times and laser intensities revealed voxel widths below 20 µm showing a similar structuring capability with high resolution of PEtOx-DA as well as for poly(ethylene glycol) diacrylate (PEG-DA) via 2PP. The properties of obtained structures were characterized by a series of line arrays as well as designed Spider-Web-patterns. PEtOx-DA revealed enhanced suitability in comparison to the used PEG-DA.