1536 Local enhancement of wound healing by extracellular vesicles modulated by gene delivery in subcutaneous macroporous scaffolds

Small extracellular vesicles (EVs) are important mediators of intercellular signaling that carry biologically active protein payloads relevant in wound healing. However, whether EVs analyzed from fluid or other biological fluids, heterogenous, reflecting part the release different cell types. To address central question EV heterogeneity parallel with unmet need forin vivo sources low platelet contamination, we have developed a macroporous scaffold for subcutaneous implantation and subsequent collection is applicable study activity any defined mouse model. Using polyvinylalcohol (PVA) sponges as scaffold, first show rapid infiltration immune cells hematopoietic origin accompanied substantial heterogenous population EVs. Second, how single vesicle flow cytometry (vFC) addresses challenge by quantifying expression surface markers map to specific subpopulations cellular origin. Third, vitro two-dimensional culture, although common, introduces significant bias addressed PVA vivomodel. Together these studies, define novel model establishing biochemical basis biology