Fig. 4

Exosome-based drug carriers for targeted resistant CRC treatment. A. a Illustration of the preparation of DOX@E-PSiNPs. DOX@PSiNPs are endocytosed into cancer cells after incubation, then localized in MVBs and autophagosomes. After MVBs or amphisomes fuse with cell membrane, DOX@E-PSiNPs are exocytosed into extracellular space. b Schematics showing how DOX@E-PSiNPs efficiently target tumor cells after intravenous injection into tumor-bearing mice. (I) DOX@E-PSiNPs efficiently accumulate in tumor tissues; (II) DOX@E-PSiNPs penetrate deeply into tumor parenchyma; and (III) DOX@E-PSiNPs are efficiently internalized into bulk cancer cells and CSCs to produce strong anticancer efficacy. c TEM images of PSiNPs and E-PSiNPs. Adopted from [94] under Creative Common Attribution License.4.0. Copyright (2019), Springer Nature. B Engineered exosome specifically target CSCs and reverse CRC drug resistance. From [95] with permission. Copyright (2020) Springer Nature