Hydrogel loaded with bone marrow stromal cell-derived exosomes promotes bone regeneration by inhibiting inflammatory responses and angiogenesis

Figure 4 Fabrication and efficacy of bone marrow-derived mesenchymal stem cell-derived exosome-treated hydrogel. A: Cells proliferation of mouse osteoblast progenitor cells (mOPCSs) with different treatments by fluorescence microscopy; B: mOPCSs with hydrogel or bone marrow-derived mesenchymal stem cell (BMSC)-derived exosome (BMSC-exo)-treated hydrogel stained by crystal violet in Transwell assays. Hydrogel + BMSC-exo enhanced cell migration, Scale bar: 50 μm; C: Alkaline phosphatase staining of mOPCSs treated with hydrogel or hydrogel + BMSC-exo for one week. Scale bar: 50 μm; D: Alizarin red staining of mOPCSs with different treatments after osteogenic induction for two weeks. Scale bar: 50 μm; E and F: mRNA and protein expression of genes associated with osteogenesis (Runx2, OPN, and Osterix) in mOPCSs with different treatments. ^aP < 0.05. BMSC-exo: Bone marrow-derived mesenchymal stem cell-derived exosome; PBS: Phosphate buffered saline; DAPI: 4’,6’-diaminido-2-phenylindole; ALP: Alkaline phosphatase.