(a) IR thermal images and (b) the corresponding temperature changes at the tumor sites of MCF-7 tumor-bearing mice under 1064 nm laser irradiation. (c) Relative tumor growth curves of the MCF-7 tumor-bearing mice in different groups [30]. (d–f) In vivo bioluminescence imaging for the 14-day growth of xenografts of 4T1-Fluc-eGFP cells implanted in nude mice post administration of Au-Iron oxide nanoparticle-loaded exosomes. (d–f) In vivo biodistribution and anti-tumor properties of tumor cell derived exosomes loaded with Au-iron oxide nanoparticles and anti-miR-21 in combination with DOX. The bioluminescence images of animals treated with exosomes without DOX (d) and with DOX (e) at days 1, 4, 8, and 12, (f) biodistribution of anti-miR-21 in different organs of animals 12 days after treatment with 3 consecutive doses (days 1, 4, and 8) [46].