Fig. 3: Characterization of tissue-bound hydrogels that formed following subcutaneous injection of PPSU microgels.
From: A biomimetic multi-component subunit vaccine via ratiometric loading of hierarchical hydrogels
a Dropping PPSU microgels (colored by ICG) onto an excised skin mimics the process of subcutaneous injection, anchoring the microgels onto tissues. b Frequency-dependent oscillatory experiments conducted in a linear viscoelastic regime. c The storage and loss moduli across the evaluated frequency range. (b-c) Rheological measurements were performed on excised samples 30 min post injection, demonstrating the in-situ formation of tertiary hydrogels. d SEM images of excised gels on day 0 (30 min post injection) and 5 days post injection. The SEM image of collagen fibers is included for comparison (ctr = control). e EDS elemental mapping of Fe3+-loaded hydrogels 30 min post injection. d, e All experiments were independently repeated three times.
