Maßgeschneidertes Biomaterial zur Imitation von Zell-Zell-Interaktionen, um die Anzucht von zirkulierenden Tumorzellen zu verbessern
Biomaterialien
Polymermaterialien
Zusammenfassung der Projektergebnisse
I report a hydrogel system which can be specifically functionalized with proteins independent of the cross-linking to mimic cell-cell interactions. The hydrogel was cross-linked using the SpyTag/SpyCatcher technology developed in the Howarth lab, which consists of a peptide and a protein that specifically and efficiently form a covalent isopeptide bond upon mixing. To functionalize the hydrogel I used SnoopTag/SnoopCatcher, an orthogonal (non-crossreacting) pair to SpyTag/SpyCatcher. For both cross-linking and functionalization no unnatural amino acids, enzymes or co-factors are required, just expressed proteins with natural amino acids. By using SpyTag/SpyCatcher fused to elastin-like polypeptides (ELPs) and in combination with hyaluronan it was possible to form hydrogels at very low solid content (<1% w/v). This allowed the formation of hydrogels with low storage modulus, required for the cell experiment. The hydrogel showed low swelling, tuneable degradation and high cell viability. Cell spreading could be tuned by integrating the RGDSP integrin binding motif into the hydrogel network. SnoopTagJr/SnoopCatcher reaction allowed efficient and site-specific coupling of complex protein ligands without interfering with the hydrogel properties. The aim of the project was to apply this hydrogel system to study cell-cell interaction in a cancer-related context. Epithelial cell adhesion molecule (EpCAM) is the major cell surface marker for circulating tumour cells (CTCs) originated from epithelial breast tissue. Also, the epithelial tissue of the mammary gland, the source of most epithelial breast cancer, is EpCAM positive. Since EpCAM gets activated by homodimerization I hypothesized, that cancer cells can influence healthy breast tissue through EpCAM. To answer this question, the hydrogel was functionalized with EpCAM and a 3D model of healthy human mammary epithelial cells established. The outcome was, that anchoring of EpCAM to the hydrogel induced dissociation of the human mammary epithelial cells. This effect was significantly reduced, when EpCAM was not immobilized to the hydrogel network, showing the experimental need for the developed hydrogel system. Coupling of an unrelated protein (maltose binding protein) to the hydrogel network had no effect, showing that the effect on the cells comes from the EpCAM. This result indicates, that EpCAM expressed on the surface of cancer cells induces dissociation of the surrounding tissue to allow cancer cell growth, spreading and migration. The modular and efficient functionalization of this hydrogel should provide a powerful platform to screen and dissect the role of cell-surface interactions in controlling cell behaviour, relevant to development, disease and organoid engineering.
Projektbezogene Publikationen (Auswahl)
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Twin Protein Superglues Give Hydrogels Mimicking Cellcell Interactions, Gordon Research Seminar – Biomaterials and Tissue Engineering, 22nd – 23rd July 2017, Holderness, USA
Wieduwild R, Howarth M
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Twin Protein Superglues Give Hydrogels Mimicking Cellcell Interactions. Gordon Research Conference – Biomaterials and Tissue Engineering, 23rd – 28th July 2017, Holderness, USA
Wieduwild R, Howarth M
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Assembling and decorating hyaluronan hydrogels with twin protein superglues to mimic cell-cell interactions. Biomaterials 2018; 180, 253-264
Wieduwild R and Howarth M
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Twin Protein Superglues Give Hydrogels Mimicking Cellcell Interactions, RSC Biomaterials Special Interest Group Annual Meeting 2018, 10th – 11th January 2018, Birmingham, United Kingdom
Wieduwild R, Howarth M
