Side-chain selenium-containing amphiphilic block copolymers: redox-controlled self-assembly and disassembly

Abstract

In this paper we report the synthesis and study of a series of side-chain selenium-containing amphiphilic poly(ethylene oxide-b-acrylic acid) block copolymers PEO-b-PAA-Se. These block copolymers can selfassemble in aqueous solution and form spherical micellar aggregates. The selenide group of PEO-b-PAA-Se can change into hydrophilic selenoxide under mild oxidation of 0.1% hydrogen peroxide, leading to the disassembly of the spherical micellar aggregates. Small compounds like Nile Red can be encapsulated into the micellar aggregates and show fast release upon the addition of 0.1% hydrogen peroxide. More interestingly, the oxidation state of selenoxide can be reversed to selenide under reduction of Vitamin C, thus recovering the spherical aggregates. The reversible oxidation and reduction process shows good reversibility and can be repeated at least 7 times. It is hoped that this reversible redox controlled system may function as nanocontainers for potential application in the areas such as responsive drug delivery and anti-oxidation studies. Experimental section MaterialsSelenium powder, sodium borohydride, triethylamine, benzyl bromide, 30% H 2 O 2 , and all other organic solvents used in this

In situ diselenide-crosslinked polymeric micelles for ROS-mediated anticancer drug delivery

“…Physically self-assembled micelles with ROS-sensitive molecules such as thioketal [23], boronic ester [22], peroxylate ester [24], thioether [25], selenoether [26], and tellurium [27], have been extensively investigated for biomedical applications. However, crosslinking might be required to achieve biostability of these polymeric micelles.…”

Reactive Oxygen Species (ROS) Responsive Polymers for Biomedical Applications

“…The Nile Red molecules encapsulated in the aggregates showed fast release under oxidative stress with the addition of H 2 O 2 . [ 29 ] Additionally, owing to the unique dual redox-sensitivities of Se Se bonds, which can be oxidized to seleninic acid in an oxidative environment (0.01% H 2 O 2 ) or reduced to selenol by reductants (0.01% GSH), the micelles based on a PEG-block -Se-Se-containing polyurethane-block -PEG triblock copolymer (PEG-b -PUSeSe-b -PEG) displayed triggered dissolution in the presence of either oxidants or reductants. [ 30 ] …”

“…Poly(propylene sulfi de) [19][20][21][22] Selenium-containing polymers [26,28,29] [ 25,30] Telluriumcontaining polymers [35][36][37] Poly(thioketal) [38][39][40]46] [ [41][42][43][44][45]55] Phenylboronic acid/ ester containing polymers Poly(L-methionine) [49] Poly(L-proline) [53,54] Macromolecular Bioscience www.mbs-journal.de and SN38 resulted in enhanced proliferation inhibition of tumor cells via inducing cell apoptosis. In addition to drug carrier, the thioether-containing particles themselves can also show inherent therapeutic properties against oxidative stress.…”

Macromolecular self-assembly and nanotechnology in China

“…More interestingly, the oxidation state of selenoxide can be reversed to selenide under reduction of vitamin C, thus recovering the spherical aggregates. The reversible oxidation and reduction process shows good reversibility and can be repeated at least seven times [46].…”

“…Xu and Zhang et al from Tsinghua University recently synthesized a series of seleniumcontaining polymers for controlled self-assembly and disassembly under various responsive stimuli [41][42][43][44][45][46]. They successfully synthesized a dual redox-responsive block copolymer with diselenide bonds located at the polymer main chains and poly(ethylene glycol) chains at both ends (PEG-PUSeSe-PEG) which can be used as drug delivery vehicles in a controlled manner [41].…”