Fig. 3: AAT elicits pro-regenerative responses in a surgical wound model of irreversible volumetric muscle loss (VML) by recruiting Il4-expressing immune cells.

a Mice with bilateral surgical resections in the quadriceps muscles were treated with direct application of an AAT scaffold or saline to the wound site immediately post-op. Animals were sacrificed after 1 week to evaluate local immune responses to the biomaterials by flow cytometry. b Gross images of healthy quadriceps muscle and VML wounds treated with either vehicle (saline) or an AAT scaffold 1-week post-injury. c Flow cytometry gating of immune populations in 4get mouse experiments (full gating in Supplementary Fig. 2). d Immune cell populations isolated from uninjured (healthy) control quadriceps muscles and muscle wounds treated with saline or an allogenic (mouse AAT, mAAT) or xenogeneic (human AAT, hAAT) ECM scaffold. e Il4 expression by percentage and median fluorescence intensity (MFI) of eosinophils and f CD4⁺ T cells isolated from wounds in 4get mice. Significance between each pair of groups is shown (p-values): * < 0.05, ** < 0.01, *** < 0.001, **** < 0.0001. Error bars represent ±1 standard deviation.