Fig. 4

a The incubation of LDEVs with Caco-2 cells led to cargo delivery from LDEVs to Caco-2 cells. Compared to mock EVs, only LDEVs treated Caco-2 group showed positive fluorescence. b The incubation of LDEVs did not cause any significant toxicity to Caco-2 cells. MTT assay was employed to examine the viability of Caco-2 cells 24 h after they were treated with mock EVs or LDEVs. c LDEVs increased gene expression of CTSB and REG3G in Caco-2 cells. At 24 h post-incubation, the RNA expression of CTSB (2.5-fold, p < 0.01) and REG3G (2-fold, p < 0.01) were significantly up-regulated in the LDEV treated group