Figure 4.

In vitro chondrogenesis of BMSCs induced by intensified stiffness and ROS production in CGQ. a) Laser confocal microscopy images of cells embedded in CGQ after treatment with PDP at various laser power densities for 3 min, wherein ROS production was assessed with DHE probe (pink color) and stronger pink fluorescence signal means more ROS; NAC (a ROS scavenger) and EAtB (1 × 10⁻³ m Elesclomol+100 × 10⁻³ m AAPH+100 × 10⁻³ m tBHP, the ROS inducer) were used; scale bar = 20 µm. b) In vitro viabilities of BMSCs cultured in CGQ scaffold after irradiation with different laser fluences for 3 min. c) Cell viability of BMSCs cultured in the different scaffolds (i.e., C, CG, and CGQ) with or without PDP for a period of 21 days (scale bar = 30 µm). d–f) mRNA expression and g) GAG content of BMSCs after different treatments for 7 days (d), 14 days (e), and 21 days (f). h) Cell skeleton staining of the cells cultured in the scaffolds with or without PDP for 21 days (scale bar = 100 µm). Mean ± SD, n = 5; *, ** and *** indicates p < 0.05, 0.01, and 0.001, respectively (C = collagen + BMSCs, CG = collagen crosslinked with genipin + BMSCs, CGQ = collagen crosslinked with genipin and QDs + BMSCs, C + PDP = collagen + BMSCs + irradiation with an 808 nm laser at fluence of 3 J cm⁻² for 3 min, CG + PDP = CG scaffold + BMSCs + irradiation with an 808 nm laser at fluence of 3 J cm⁻² for 3 min, CGQ + PDP = CGQ scaffold + BMSCs + irradiation with an 808 nm laser at fluence of 3 J cm⁻² for 3 min).