Prof. Dr. rer. nat Jürgen Groll, Department for Functional Materials in Medicine and Dentistry, University Hospital Würzburg, Würzburg, Germany

Soft Biomaterials for Drug Delivery and Biofabrication

Water is the main constituent of the human body, accounting for about 2/3 of its weight in per cent. This high water content is crucial for tissue hemostasis and can only be maintained together with the necessary mechanical strength by a combination of self-assembly and macromolecular cross-linking. While self-assembly is most important in cellular and sub-cellular dimensions, the tissue-level is governed by macromolecular networks, both in fibrillary form and as hydrogels as main components of the extracellular matrix.

Hydrogels are three-dimensionally cross-linked hydrophilic polymer networks that can swell up to more than 90% weight content with water. Cells can be embedded into hydrogels, and cell encapsulation by hydrogels has been an active field of research for decades. Only recently, the combination with 3D printing has led to development of printable hydrogels for direct generation of hierarchical structures. Moreover, the polymer network in hydrogels protects embedded bioactives such as proteins and peptides from degradation, and the degradability of the network can be adjusted through the chemical design of the polymers and the choice of cross-linking mechanism. Nanogels, hydrophilic cross-linked hydrogel-particles, may thus be exploited for delivery of peptides and proteins. This lecture will give an overview on the activities of my group in the field of soft biomaterials with the focus on nanogels for drug delivery, fibrous artificial ECM and approaches to 3D-printable thermoplasts and hydrogels for biofabrication.

References:
[1] Singh, S.; Topuz, F.; Hahn, K.; Albrecht, K.; Groll, J.: Embedding of Active Proteins and Living Cells in Redox-Sensitive Hydrogels and Nanogels through Enzymatic Cross-Linking. Angewandte Chemie International Edition (2013) 52, 3000.
[2] Kuhlmann, M.; Reimann, O.; Hackenberger, C.P.R.; Groll, J.: Cysteine-functional Polymers via Thiol-Ene Conjugation. Macromolecular Rapid Communications 2015, 36 (5), 472−476.
[3] G. Hochleitner, T. Jüngst, T. D. Brown, K. Hahn, C. Moseke, F. Jakob, P. D. Dalton, J. Groll: Additive Manufacturing of Scaffolds with Sub-micron Filaments via Melt Electrospinning Writing. Biofabrication 2015, 7, 035002.
[4] F. Chen, G. Hochleitner, T. Woodfield, J. Groll, P. Dalton, B. G. Amsden: Additive Manufacturing of a Photo-Cross-Linkable Polymer via Direct Melt Electrospinning Writing For Producing High Strength Structures. Biomacromolecules 2016, 17 (1), 208–214.
[5] D. Grafahrend, K.-H. Heffels, M.V. Beer, P. Gasteier, M. Moeller, G. Boehm, P.D. Dalton, J. Groll: Degradable polyester scaffolds with controlled surface chemistry combining minimal protein adsorption with specific bioactivation. Nature Materials 2011, 10, 67-73.
[6] A. Rossi, L. Wistlich, K.-H. Heffels, H. Walles, J. Groll: Isotropic versus bipolar functionalized biomimetic artificial basement membranes and their evaluation in long term human cell co-culture. Advanced Healthcare Materials 2016, 5(15), 1939-1948.
[7] K. Schacht, T. Jüngst, M. Schweinlin, A. Ewald, J. Groll, T. Scheibel: Biofabrication of Cell-loaded, 3D Recombinant Spider Silk Constructs. Angewandte Chemie International Edition 2015, 54 (9),2816.
[8] T. Jüngst, W. Smolan, K. Schacht, T. Scheibel, J. Groll: Strategies and Molecular Design Criteria for 3D Printable Hydrogels. Chemical Reviews 2016, 116 (3), 1496–1539.
[9] S. Stichler, T. Jungst, M. Schamel, I. Zilkowski, M. Kuhlmann, T. Böck, T. Blunk, J. Teßmar, J. Groll: Thiol-ene clickable poly(glycidol) hydrogels for biofabrication. Annals of Biomedical Engineering 2017, 45(1), 273-285.

Biography:
Prof. Jürgen Groll holds the chair for Functional Materials in Medicine and Dentistry at the University of Würzburg. His research interest comprises applied polymer chemistry for life sciences, biomimetic scaffolds, immunomodulation, nanobiotechnology, and biofabrication. Within biofabrication, he coordinates the large European integrated project HydroZONES that focuses on the printing of layered constructs for cartilage regeneration. Since 2014, he also holds the ERC consolidator grant Design2Heal that concerns the evaluation of design criteria for immunomodulatory scaffolds.

Prof. Groll received his Ph.D. from the RWTH Aachen University with summa com laude in 2005. From 2005 to 2009, he worked in industry in the field of functional coatings and biocomposite materials. In parallel, he built up a research group on polymeric biomaterials at the DWI Interactive Materials Research Institute in Aachen. He is board member of the international society for biofabrication and editorial board member of the journal Biofabrication. His work has been recognized by several awards such as the Bayer Early Excellence in Science Award 2009, the Reimund-Stadler award of the Division of Macromolecular Chemistry of the German Chemical Society in 2010 and the Unilever Prize of the Polymer Networks Group in 2014.

Host: Associate professor Alexander Zelikin, Department of Chemistry, Aarhus University