14.3.5 Stimuli-Responsive Delivery Systems
Stimuli responsiveness is a very common phenomenon in nature, as are pH responsiveness, light responsiveness, electricity responsiveness, and so on. These responsiveness actions can also be employed in drug delivery and release. The most
Fig. 11 Tumor cell targeting and therapeutic strategy using hyaluronic acid–ceramide
(HACE)–methyl β-CD (MbCD) nanoparticles [58]
Strands are held together via guest-host
complexes between CPT and cyclodextrin
PEG provides “stealth” against
immune recognition
Self-assembly:
Approx. 4-5 strands
form one
nanoparticle
Potent Topo-1 inhibitor
camptothecin (CPT)
Prolonged release of CPT inside tumor cells by linkerhydrolysis,resulting in sustained inhibition of Topo-1 and HIF-1α
ca. 20-40nm
Cryo-Electron Microscopy
image of CRLX101
Polymer-Drug
Assembly
CD
PEG 3400
PEG 3400
CD
CD
CPT
Linker
Linker
Linker
Linker
Linker
Linker
CPT
CPT
CPT
CPT
CPT
n
Fig. 12 Cyclodextrin (CD), polyethylene glycol (PEG), and camptothecin (CPT) conjugate
assembled nanoparticles [62]
410
J. Liu et al.