Acellular Adipose Tissue promotes anti-fibrotic remodeling in Phase II Study

Acellular Adipose Tissue (AAT) is an off-the-shelf, cadaveric adipose-derived ECM-based biomaterial for soft tissue reconstruction. AAT has been validated preclinically to promote angiogenesis and adipogenesis and demonstrated safety, biocompatibility, and tolerability in a Phase I study. In this study we report the findings for the first ten patients in the Phase II study for permanent reconstruction of modest soft tissue defects. AAT promoted macrophages, CD3⁺ T cells, and CD34⁺ progenitor activity. Multiplex immunofluorescence staining using the PhenoCycler (formerly CODEX) imaging platform found that AAT can induce tertiary lymphoid structures (TLS). Nanostring GEOMx spatial transcriptional data analysis found significant differential gene expression between neighboring tissues with <i>EGR1</i>, <i>MCL1</i>, and <i>NR4A1</i> upregulated in AAT. These genes have roles in angiogenesis, anti-apoptotic processes, and promotion of anti-inflammatory genes, respectively. AAT promoted anti-fibrotic CD74⁺ adipose-derived stromal cells, confirmed by immunofluorescence staining. Our findings demonstrate that AAT promotes angiogenesis, adipogenesis, and anti-fibrotic remodeling.