82
Z. Liu and Y. Liu
Fig. 4.2 a The general construction strategies of aptamer-drug conjugates. b A structural illustration of aptamer-drug conjugates linked with linker. Reprinted with permission from Ref. [32]
Copyright 2015, The American Chemical Society. c Aptamer-paclitaxel conjugate. [33] Copyright
2017, Springer Nature. d Aptamer-mitomycin C conjugate in which drugs were covalently bound
to aptamer. Reprinted with permission from Ref. [35] Copyright 2020, American Chemical Society.
e Sgc8 aptamer-pyropheophorbide A conjugates showed tumor spheroid targeting and penetration
abilities for photodynamic therapy. Reprinted with permission from Ref. [36] Copyright 2020,
American Chemical Society. f Aptamer-5-FU conjugate with a photocleavable linker (structures
shown in inlet) via automated synthesis. Reprinted with permission from Ref. [32] Copyright 2015,
The American Chemical Society
ApDCs (Fig. 4.2f) [37]. Specifically, a phosphoramidite containing a therapeutic
agent 5-FU was synthesized with a photocleavable linker to realize controlled drug
release. The elaborately designed phosphoramidites were used as building blocks
during the synthesis of Sgc8 aptamer, therefore one ApDC carrying multiple drug
copies was constructed. The modular ApDCs specifically delivered anticancer agents
into PTK7
+ HCT116 cell, and consequently inhibited the cell proliferation under
light irradiation. This study realized increased drug loading efficiency of ApDCs,
providing a promising strategy to reduce the cost.
Another big concern of ApDCs is the stability in vivo, because single-stranded
aptamers usually suffer from easy degradation by plasma exonucleases. Although
Z. Liu and Y. Liu
Fig. 4.2 a The general construction strategies of aptamer-drug conjugates. b A structural illustration of aptamer-drug conjugates linked with linker. Reprinted with permission from Ref. [32]
Copyright 2015, The American Chemical Society. c Aptamer-paclitaxel conjugate. [33] Copyright
2017, Springer Nature. d Aptamer-mitomycin C conjugate in which drugs were covalently bound
to aptamer. Reprinted with permission from Ref. [35] Copyright 2020, American Chemical Society.
e Sgc8 aptamer-pyropheophorbide A conjugates showed tumor spheroid targeting and penetration
abilities for photodynamic therapy. Reprinted with permission from Ref. [36] Copyright 2020,
American Chemical Society. f Aptamer-5-FU conjugate with a photocleavable linker (structures
shown in inlet) via automated synthesis. Reprinted with permission from Ref. [32] Copyright 2015,
The American Chemical Society
ApDCs (Fig. 4.2f) [37]. Specifically, a phosphoramidite containing a therapeutic
agent 5-FU was synthesized with a photocleavable linker to realize controlled drug
release. The elaborately designed phosphoramidites were used as building blocks
during the synthesis of Sgc8 aptamer, therefore one ApDC carrying multiple drug
copies was constructed. The modular ApDCs specifically delivered anticancer agents
into PTK7
+ HCT116 cell, and consequently inhibited the cell proliferation under
light irradiation. This study realized increased drug loading efficiency of ApDCs,
providing a promising strategy to reduce the cost.
Another big concern of ApDCs is the stability in vivo, because single-stranded
aptamers usually suffer from easy degradation by plasma exonucleases. Although