Figure 5. MSC spheroids entrapped in sulfate-modified alginate hydrogels enhance myoblast infiltration.
(a) MSC spheroids were entrapped and cultured in alginate hydrogels for 4 days, then tdTomato-expressing myoblasts were introduced to the media and cultured for an additional 8 days. (b) Representative z stack 3D reconstruction images of tdTomato myoblasts within MSC spheroid gels on day 8 (scale bar = 100 μm). (c) Pixel sum of tdTomato fluorescence, (d) depth of penetration and (e) sphericity of the infiltrating myoblasts were quantified from the z stacks, confirming greater myoblast invasion and elongation in 2% sulfated gels. (f-j) The experiment was repeated with spheroids that were killed after 4 days of culture to confirm that GF retention induced myoblast infiltration. Data are mean ± SD (n=9–1145). Groups with statistically significant differences do not share the same letters; ns denotes no significance among all groups.