Redox/pH dual stimuli-responsive biodegradable nanohydrogels with varying responses to dithiothreitol and glutathione for controlled drug release.
A new type of redox/pH dual stimuli-responsive poly(methacrylic acid) (PMAA)-based nanohydrogels was prepared from methacrylic acid and N,N-bis(acryloyl)cystamine crosslinker via distillation-precipitation polymerization. The nanohydrogels could be easily degraded into individual linear short chains (M(n) ≈ 1200, M(w)/M(n) < 1.1) in the presence of 10 mM dithiothreitol (DTT) or glutathione (GSH). Doxorubicin (DOX) as a model anti-cancer drug was high efficiently loaded into the nanohydrogels (up to 42.3 wt%) due to the strong electrostatic interactions between the amine group in doxorubicin (DOX) and the carboxyl groups in the nanohydrogels at a physiological pH. The cumulative release profile of the DOX-loaded nanohydrogels showed a low level of drug release (less than 15 wt% in 24 h) at pH 7.4, and was significantly accelerated at a lower pH (5.0) and reducing environment (over 91 wt% in 5 h), exhibiting an obvious pH/redox dual-responsive controlled drug release capability. The drug release behavior of the DOX-loaded nanohydrogels in the presence of GSH was very different from the DTT as the loaded DOX could be quickly released in the presence of GSH, but not in DTT. The possible reason is the synergic effect of reduction and charge exchange of GSH at a low pH. The dose-dependent cytotoxicity of the DOX-loaded nanohydrogels was studied by the CCK-8 assay; the DOX-loaded nanohydrogels could be taken up quickly by human glioma (U251MG cells) via endocytosis, and then biodegraded to release the loaded drugs, which exhibited a comparably anti-tumor efficacy. These nanohydrogels possess many favorable traits, such as excellent biocompatibility and biodegradability, adequate drug loading capacity, minimal drug release under an extracellular condition (non-reductive), and rapid drug release in response to the intracellular level of pH and reducing potential, which endow them as a promise candidate for delivering anti-cancer drugs.
State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Laboratory of Advanced Materials, Fudan University, Shanghai 200433, China.
Yuan-Jia
YJ
Pan
Yuan-Yuan
YY
Chen
Dong-Rui
DR
Wang
Chuan
C
Wei
Jia
J
Guo
Da-Ru
DR
Lu
Chih-Chang
CC
Chu
Chang-Chun
CC
Wang
D001672:Biocompatible Materials / Q000737:chemistry*; D001673:Biodegradation, Environmental; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003432:Cross-Linking Reagents / Q000737:chemistry; D003692:Delayed-Action Preparations; D004220:Disulfides / Q000737:chemistry; D004229:Dithiothreitol / Q000494:pharmacology*; D004317:Doxorubicin / Q000737:chemistry / Q000494:pharmacology; D005978:Glutathione / Q000494:pharmacology*; D057809:HEK293 Cells; D006801:Humans; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D008856:Microscopy, Fluorescence; D008858:Microscopy, Phase-Contrast; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction / Q000187:drug effects; D011109:Polymethacrylic Acids / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D003692:Delayed-Action Preparations; D004220:Disulfides; D020100:Hydrogels; D011109:Polymethacrylic Acids; C030613:polymethacrylic acid; D004317:Doxorubicin; D005978:Glutathione; D004229:Dithiothreitol