Oxidative stimuli-responsive nanoprodrug of camptothecin kills glioblastoma cells.
The purpose of this study was to prepare and characterize nanometer-sized prodrug (nanoprodrug) of camptothecin. The camptothecin prodrug was synthesized using tetraethylene glycol spacer linked via carbonate bond to camptothecin and via ester bond to alpha-lipoic acid. The nanoprodrug was prepared through the spontaneous emulsification mechanism using the mixture of camptothecin prodrug and alpha-tocopherol which served as a structural matrix. The nanoprodrug was activated readily by porcine liver esterase and, with a much slower rate, by hydrolytic degradation. Upon longterm storage, the alpha-lipoic acid moiety of the camptothecin prodrug gradually oxidized without loss of structural integrity and therapeutic efficacy. Interestingly, the hydrolytic activation was negligible before the oxidation, but was significantly accelerated after the oxidation of the alpha-lipoic acid moiety, suggesting an oxidative stimuli-responsive activation of the prodrug. The camptothecin nanoprodrug was found to possess significant inhibitory effect on the proliferation of U87-MG glioma cells with an IC(50) of 20 nM.
Lee
Bong-Seop
BS
Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
Nalla
Aruna K
AK
Stock
Ilana R
IR
Shear
Talia C
TC
Black
Keith L
KL
Yu
John S
JS
D000970:Antineoplastic Agents / Q000494:pharmacology*; D002166:Camptothecin / Q000494:pharmacology*; D045744:Cell Line, Tumor; D005909:Glioblastoma / Q000473:pathology*; D006801:Humans; D036103:Nanotechnology; D018384:Oxidative Stress; D011355:Prodrugs
D000970:Antineoplastic Agents; D011355:Prodrugs; D002166:Camptothecin