Understanding the link between fibre structure and viscoelasticity in PEGMAL hydrogels

The extracellular matrix (ECM) provides a niche for tissue-resident cells, comprising various components such as water, polysaccharides, and structural proteins like fibronectin (FN), which offer both structural and functional support. Natural ECMs are viscoelastic and exhibit stress relaxation properties. However, synthetic hydrogels commonly used for 3D cell culture tend to be purely elastic. Therefore, there is a growing need for viscoelastic hydrogels that better replicate ECM behaviour in vitro. We wish to compare the scattering from the primary assembled structures and any potential network changes to gels upon relaxation after a strain is applied. SANS is the preferred technique as it can be performed on the self-assembled structures in-situ compared to drying them for microscopy, which can alter the aggregation and result in drying artefacts. We wish to gel our samples on the rheometer and collect RheoSANS on these samples as they gel. We also wish to probe how these gels relax in response to strain. RheoSANS allows us to directly correlate the structural changes with the evolving rheology, which is not possible with static or offline measurements. In their entirety, these experiments will provide us with crucial information to further understand our gel systems to better tailor our hydrogels to mimic the bone marrow niche.