fig3

Figure 3. Bioprinted sEVs constructs promoted osteogenesis, immunomodulation and angiogenesis, key processes in bone regeneration. (A) Micro-CT reconstruction and histomorphological analysis of bioprinted GelMA + d-ECM + BMSCs-sEVs constructs in rabbit subchondral bone repair. Adopted from Ref.^[34]. Scale bars = 100 μm; (B) Immunofluorescence staining of wound tissues showing pro-inflammatory (CD86, NOS2) and anti-inflammatory (CD163, CD206) markers at different time points in a rat subcutaneous wound healing model treated with bioprinted COL + d-ECM + M2-sEVs constructs. Adopted from Ref.^[38]. Scale bar = 100 μm; (C) Bioengineered vessel structures stained with VE-cadherin (Red) and Isolectin B4 (Green), induced by bioprinted GelMA + alginate + HUVECs-sEVs constructs. Adopted from Ref.^[37]. GelMA + d-ECM + BMSCs-sEVs: BMSCs-sEVs laden in GelMA and cartilage-derived d-ECM; COL + d-ECM + M2-sEVs: M2-sEVs laden in collagen type-1 and chicken skin-derived d-ECM; GelMA + alginate + HUVECs-sEVs: HUVECs-sEVs laden in GelMA and alginate; sEVs: small extracellular vesicles; GelMA: gelatin methacryloyl; d-ECM: decellularized extracellular matrix; BMSCs: bone marrow mesenchymal stem cells; COL: collagen type I; M2: M2 macrophage phenotype; VE-cadherin: vascular endothelial cadherin; HUVECs: human umbilical vein endothelial cells.