Post‐Assembly of Oxidation‐Responsive Amphiphilic Triblock Polymer Containing a Single Diselenide

Abstract

Linear amphiphilic triblock polymers containing a single diselenide (SeSe‐tri‐ABP) are synthesized by coupling reactions. They self‐assemble into spherical micelles 1 in aqueous solution. A remarkable morphology transformation of the micelles is confirmed through dynamic light scattering (DLS) and transmission electron microscopy (TEM). The release behavior of a model molecule, Rhodamine B (RB), is studied by UV–vis spectrophotometry. It is found that post‐assembly from micelles 1 to micelles 2 is induced by the oxidation‐responsive cleavage of the diselenide group in the oxidation solution. Interestingly, the RB release studies reveal that these micelles release RB in a diphasic pattern (slow after initial fast release) within 24 h under an oxidative environment. In contrast, minimal drug release (<20%) is observed within 24 h for SeSe‐tri‐ABP micelles under aqueous conditions. Meanwhile, this release behavior of the RB‐loaded micelles can be tuned by the post‐assembly of oxidation‐responsive SeSe‐tri‐ABP in different oxidation conditions, providing a promising platform for controlled delivery of nanocarriers.

Redox poly(ethylene glycol)-b-poly(l-lactide) micelles containing diselenide bonds for effective drug delivery

“…It was found that M-P-Se/DTX displayed a slow-level release rate and exhibited a lower cumulative release ratio of DTX (less than 40 % over 24 h) in the absence of GSH, and DTX was released due to the diffusion mechanism [27]. On the contrary, DTX release rate increased obviously at the presence of GSH, and higher GSH concentration induced the faster DTX release.…”

2,2′‐Dipyridyl diselenide: A chemoselective tool for cysteine deprotection and disulfide bond formation

“…PySeSePy is not commercially available. Thus, we began with the synthesis of PySeSePy by first reducing elemental selenium with sodium borohydride and then introducing 2‐bromopyridine for a nucleophilic displacement reaction, using reported methodologies . The synthesis was completed giving 49% yield.…”

“…PySeSePy was synthesized following previously reported methods . Water (20 mL), in a round‐bottom flask containing 0.596 g (15.75 mmol) of sodium borohydride, was cooled on ice to 0 °C.…”

Smart polymers in drug delivery systems on crossroads: Which way deserves following?

“…The dialkylsulfide-based systems are mostly composed of poly(propylene sulfide) [172]. An interesting case is polymers containing diselenide bonds that are responsive to both oxidative and reductive environments [173][174][175][176] and also to gamma radiation [177].…”