Figure 6.

(A) Working principle of csUCNP@C nanocomposite for high-accurate PTT at facile temperature. (B) Thermal images of nude mice with (left panel) and without (right panel) csUCNP@C-labelled HeLa cell tumors. (C) Representative photos of nude mice transplanted with csUCNP@C-labelled HeLa cells. (D) H&E stained tumor sections of the border of tumor and normal fat tissue. The tumor region (Tu) and the adipocytes (Ad) in normal fat tissue of the mice without irradiation (left, Control) is compact and the tumor cells are stretched. Following photothermal treatment (middle, Facile PTT), the tumor region became loose and fragile and the tumor cells are atrophic. The adipocytes (Ad) in normal fat tissue are intact with minimal damage. However, following high-power irradiation, both Tu and Ad suffered extreme damage (right, Over irradiated). All irradiation processes were under 730-nm and 0.3 Wcm⁻² except high-power (0.8 Wcm⁻²). Reproduced from Zhu X, Feng W, Chang J, et al. Temperature-feedback upconversion nanocomposite for accurate photothermal therapy at facile temperature. Nat Commun. 2016;7:10437. Creative Commons license and disclaimer available from: http://creativecommons.org/licenses/by/4.0/legalcode“http://creativecommons.org/licenses/by/4.0/legalcode.⁷⁵