Fig. 7: Hydrogel FBR with recruited CD13-positive cells leads to hydrogel resorption.
a, b Survey and detail images show qualitative reductions in size of DCHK deposit and L-NIO-induced infarct, but not of DCHMO deposit at 6 weeks after injection c, d. Survey and detail images show DCHMO deposit remains unresorbed up to 12 weeks after injection. e Quantification of GFAP-positive cell border thickness at lateral (gray matter) or medial (internal capsule) borders at 6 weeks. *P = 0.0469 and **P = 0.0021 (lateral), = 0.0012 (medial), and ***P = 0.0001 versus DCHMO on same side; not significant (NS) between DCHMO on either side, **P = 0.0012 for border location effect across all samples, two-way ANOVA with Tukey (n = 5, 4, 4 mice for DCHMO, DCHK, and L-NIO, respectively). f Quantification of change in hydrogel radius for DCHMO and DCHK from 2 to 42 days. NS, ***P = 0.0001 and ***P < 0.0001 for DCHK versus DCHMO at 7 and 42 days, respectively; NS for DCHMO at 7 versus 42 days and for DCHMO versus DCHK at 2 days, two-way ANOVA with Bonferroni. g Quantification of change in total CD13 for DCHMO and DCHK from 2 to 42 days. **P = 0.0067 and ***P < 0.0001 for DCHK versus DCHMO at the same timepoints. NS between the various timepoints for DCHMO, two-way ANOVA with Bonferroni. For both f and g, n = 9, 10, 5 mice for DCHMO at 2, 7, and 42 days; n = 9, 12, 5, 4 mice for DCHK at 2, 7, 21, 42 days. h Schematic of microgel particle (MP) synthesis involving inverse emulsion of polyethylene glycol (PEG)-based thiol and acrylate functionalized oligomers that react via Michael addition. MP can be readily suspended in hydrogels. i, j Survey images of FBR to DCHMO loaded with MP at 1 week and 6 weeks show that incorporation of MP into DCHMO leads to recruitment of CD13-positive cells and hydrogel resorption. k Quantification of effect of incorporation of MP(+) on total CD13-positive cell response for DCHMO and DCHK at 1 week. NS and ***P < 0.0001, two-way ANOVA with Bonferroni, n = 10, 6, 12, and 9 mice for DCHMO, DCHMO + MP, DCHK and DCHK + MP, respectively. All graphs show mean ± s.e.m with superimposed individual data points.
