Figure 4.

(A) Illustration of photo/chemo combination therapy via in situ formed thermal-sensitive polymer hydrogel (TNP) in a xenograft tumor model. Doxorubicin and zinc phthalocyanine loaded TNP polymer solution is transformed to gel state after injecting, to be used for localized photodynamic therapy. Adapted with permission from Huang et al. [77]; (B) relative tumor volume of the mice model in different treatment conditions showing the significance of concurrent localized chemo/PDT therapy. Adapted with permission from Huang et al. [77]. (C) Thermal fluctuations and corresponding on/off switch release of drug from thermo-responsive PIPAAm-PBMA micelles through the low critical solution temperature (LCST). Adapted with permission from Chung et al. [82]. (D) Hydrazide-functionalized poly N-isopropylacrylamide (PNIPAAm) microgels in a magnetic nanoparticle-containing matrix using for pulsatile on/off release of drugs in response to an external magnetic field. Adapted with permission from Campbell et al. [83]. (E) Ex vivo setup of the light-triggered release of the skin patch with drug reservoirs containing rhodamine-loaded hydrogel beads. It is shown that by the exposure of the visible light (LED lamp (30 mW·cm ⁻²) for 6 h), rhodamine is released from the Polydimethylsiloxane (PDMS)skin patch, which is significantly higher than that of “off “condition. Adapted with permission from Kim et al. [89].