Fig. 1. Surfactants used to form catanionic vesicles. (a) AZO TAB; (b) SDBS; (c) SDS[21]

Fig. 2. Structure of poly azobenzene dendrimers[24]

Fig. 3. Molecular structure of P(AAm-co-VDT-co-SPAA) hydrogels[26]

Fig. 4. (a) Disassembly of βCD/AZO complex irradiated by UV light and Fc competitive unsheathing; (b) corresponding target DNA released from βCD/AZO upon UV light and Fc addition[23]

Fig. 5. (a) Synthesis of (2-nitro-1,3-phenylene) bis (methylene) diacrylate; (b) library of photo-responsive PBAEs (P1-P16) and various side charged groups[42]

Fig. 6. Adsorption and release process of DNA[43]

Fig. 7. Intracellular kinetics of PDMNBLG-r-PVBLG- 8/DNA complexes[44]

Fig. 8. Release of EGFP DNA caused by shape transformation of EGFP-GNR conjugates in cells irradiated by NIR laser[51]

Fig. 9. Selective release of DNA-conjugated nanorods under different NIR irradiation[52]

Fig. 10. (a) Plasmid DNA and siRNA caged by DMNPE are released by upconverted UV light from NIR light; (b) loading of caged plasmid DNA/siRNA into mesopores of UCNs[56]

Fig. 11. (a) Synthesis processes of Si-UCNPs;(b) DNA/siRNA adsorbed on particle surface are released by upconverted UV light[57]

Fig. 12. Formation of Alkyl-PEI2k-Cdots/siRNA complex and progress of being delivered into cancer cell[59]

Fig. 13. (a) Chemical structure and photolysis of 2-nitrobenzyl-containing amphiphilic block copolymer; (b) photo-controlled release of an encapsulated agent[60]

Fig. 14. Synthesis of PEO-dendritic DNQ[61]