In our group, we actively develop a library of polymeric biomaterials based on poly(ethylene glycol) (PEG), which is well-known as a highly hydrophilic hydrogel.
We work with linear and multi-arm PEG monomers. These gels are characterized by their ability to take up water and swollen gels may contain more than 90% water. Their mechanical properties can be tuned by varying the crosslinking density, and due to their softness and high water content these hydrogels closely resemble living tissue. Combined with their cytocompatibility, these materials are excellent biomaterials. We also prepare blends with PEG-based polymers; these blends permit to easily tune their properties by adjusting the ratio between components, resulting in highly versatile materials.
Traditionally, these polymers have been crosslinked by UV-curing (reaction between their ending acrylate groups). However, we have introduced different functional groups to our monomers, in order to enable different crosslinking chemistry, such as “click chemistry”, as well as to modify the final properties of the gels, e.g. biodegradability.
Development of novel biomaterials
In parallel, we work with a very hydrophobic fluoropolymer, namely perfluoropolyether (PFPE). The PFPE-based fluoropolymer is also an interesting biomaterial, e. g. for biomedical implants, since it doesn’t swell in water, is inert to chemical degradation and is both hydrophobic and oleophobic. Based on these properties, undesired protein adsorption and adhesion of unwanted cells is suppressed.
Besides the potential bioapplications of this material, the fluoropolymer is an excellent material for soft (nano)lithography, e. g. in replica molding.
Fang Ren, Cigdem Yesildag, Zhenfang Zhang, Marga C. Lensen “Functional PEG-Hydrogels Convey Gold Nanoparticles from Silicon and Aid Cell Adhesion onto the Nanocomposites” Chem. Mater., 2017, 29(5): 2008-2015. DOI: 10.1021/acs.chemmater.6b03548
Changzhu Wu, Christine Strehmel, Katharina Achazi, Leonardo Chiappisi, Jens Dernedde, Marga C. Lensen, Michael Gradzielski, Marion B. Ansorge-Schumacher, and Rainer Haag* "Enzymatically Crosslinked Hyperbranched Polyglycerol Hydrogels as Scaffolds for Living Cells" Biomacromolecules, 2014, 15(11): 3881-3890. DOI: 10.1021/bm500705x
Zhenfang Zhang, Axel Loebus, Gonzalo de Vicente, Fang Ren, Manar Arafeh, Zhaofei Ouyang and Marga C. Lensen* "Synthesis of Poly(ethylene glycol)-based Hydrogels via Amine-Michael Type Addition with Tunable Stiffness and Postgelation Chemical Functionality" Chem. Mater., 2014, 26(12): 3624–3630. DOI: 10.1021/cm500203j
Susan Kelleher, Zhenfang Zhang, Axel Löbus, Christine Strehmel and Marga C. Lensen* "Blending PEG-based polymers and their use in surface micro-patterning by the FIMIC method to obtain topographically smooth patterns of elasticity" Biomaterials Science, 2014, 2(3): 410–418. DOI: 10.1039/c3bm60218d
Vera A. Schulte, Mar Diez, Martin Möller, Marga C. Lensen* "Topography induced cell adhesion to Acr-sP(EO-stat-PO) hydrogels: the role of protein adsorption" Macromolecular Bioscience, 2011, 11(10): 1378–1386. DOI: 10.1002/mabi.201100087
Vera A. Schulte, Yibing Hu, Mar Díez, Daniel Bünger, Martin Möller and Marga C. Lensen* "A hydrophobic perfluoropolyether elastomer as a patternable biomaterial for cell culture and tissue engineering" Biomaterials, 2010, 31(33): 8583 – 8595. DOI: 10.1016/j.biomaterials.2010.07.070
Marga C. Lensen,* Petra Mela, Ahmed Mourran, Juergen Groll, Jean Heuts, Haitao Rong, Martin Möller: "Micro- and Nanopatterned Star Poly(Ethylene Glycol) (PEG) Materials Prepared by UV-Based Imprint Lithography", Langmuir, 2007, 23(14): 7841-7846. DOI: 10.1021/la7007683
We also study the incorporation of metallic and inorganic nanoparticles into our gels in order to combine the unique properties of both materials (nanoparticle and gel). These composite materials are of great interest for biomedical and analytical applications.