| Popis: |
Rationally designed polypeptide-based materials have advantages over other biomaterials for their ability to be engineered from the bottom-up, and to be tailored to the needs of specific potential applications. Based on previous works in the Woolfson laboratory on self- assembling peptide fibres (SAF), this research project focused on developing coiled-coil- based fibrillar hydrogel networks called hydrogelating SAFs (hSAFs), and applying them to more-complex biological systems, notably in cell culture. The hSAFs were tested as a three- dimensional cell-culture scaffold with the aim of mimicking the microenvironment provided by native extracellular matrix (ECM). hSAFs were shown to support growth and differentiation of neuronal cells. Furthermore, a design strategy was explored on how to couple short biomimetic peptides to these proteinogenic scaffolds to enhance cell-matrix interactions. This was achieved by integrating the well-studied cell-adhesion motif RGDS (Arg-Gly-Asp- Ser) to hSAFs using bioorthogonal copper-based click chemistry. Addition of such biomimetic peptides did not alter folding, fibre formation, and higher-order assembly (gelation) of the hSAFs. The resulting functionalised gels promoted early differentiation and longer neurite-like outgrowth in PC12 cells, and of primary rat hippocampal cells. The attached biomimetic peptide was functional and elicited the desired cellular response. Another short biomimetic peptides, i.e. the laminin-derived IKVAV (lIe-Lys-Val-Ala-Val), which supports neurite growth, was also successfully incorporated into hSAFs and gels. Thus, we have demonstrated a chemically defined, bottom-up approach to biological scaffold synthesis and assembly, and further the use of straightforward techniques to incorporate specific biomolecular signals under physiological conditions. Although conditions will need to be optimised for different cell types, hSAF gel formation and functionalisation via click chemistry promise a robust platform in cell-culture studies and potentially for tissue engineering. |
