Periodic Reporting for period 2 - BIOGEL (Engineering responsive and biomimetic hydrogels for biomedical therapeutic and diagnostic applications)
Reporting period: 2017-01-01 to 2018-12-31
(ii) More efficient cell adhesive bicyclic peptides were synthesized (doi: 10.1021/acscombsci.8b00144) with a newly developed technique to measure binding efficiency (doi: 10.1021/acs.analchem.7b00554). For the purpose of cartilage repair, two injectable hydrogels were developed: One is a hybrid Silk Elastin-Like co-Recombinamer hydrogel (doi: 10.1021/acs.biomac.8b01211) which can be post-modified with the bicyclic peptides yielding in enhanced cell adhesion (doi: 10.1088/1748-605X/aafd83). The second gel is an injectable hyaluronic acid-based hydrogel with tunable biochemical and mechanical properties (doi: 10.1016/j.eurpolymj.2019.02.024). In addition to these biological gels, synthetic gels were developed to better mimic the non-linear mechanics of the natural ECM. Fibrous, macroporous polyisocyanides (PIC) hydrogels were synthesized with stress-stiffening behavior, regulating cell behavior (doi: 10.1021/acs.biomac.8b01445). A combination of PIC with the bicyclic peptides accelerates stem cell spreading (doi: 10.1038/s41467-019-08569-4). The mechanical properties and gelation temperature can be tailored by copolymerization (doi: 10.1016/j.cclet.2017.11.002). Another method to obtain macropores in an injectable material is by crosslinking micron-scale microgels together after injection. Novel microfluidic techniques were established to produce hollow and rod-shaped microgels that enable drug and cell encapsulation directly on chip (doi: 10.1039/c7bm00322f). In order to mimic the tissue architecture, bioactive domains are patterned into 3D poly(ethylene glycol) hydrogels using light-sensitive chemistry. To test the efficiency of the novel Biogel hydrogels ex vivo, a new bioreactor platform was created. Nanocellulose-based hydrogels were successfully employed to culture and differentiate human liver organoids. In addition, an isolated perfused porcine liver platform was realized.
(iii) Poly (N-isopropylacrylamide) (pNIPAM)-based thermosensitive hydrogels, embedded with gold nanoparticles, were prepared as hydrogel films that can locally actuate upon irradiation to study mechanobiology. Nanopatterned pNIPAM microgel surfaces leads to controlled bending of microgels upon actuation. The same pNIPAM/gold material was employed to design new diagnostic devices with improved sensitivity (doi: 10.1039/C7NR08905H). In parallel, a portable optical biosensor platform was established for label-free detection of proteins. Additionally, ELRs with both a lower and upper critical solution temperature were produced with potential use as responsive temperature sensors. A last sensing approach targeted the degradability of specific peptide patterns incorporated into the ELR backbone to detect different proteases.