Water-soluble complexes formed from hydrogen bonding interactions between a poly(ethylene glycol)-containing triblock copolymer and poly(methacrylic acid)

Abstract

Poly(sodium styrenesulfonate)-block-poly(ethylene glycol)-block-poly(sodium styrenesulfonate) (PSS-PEG-PSS) was prepared via reversible addition-fragmentation chain transfer (RAFT) radical polymerization of sodium styrenesulfonate (SS) using a poly(ethylene glycol) (PEG)-based bifunctional macro-chain transfer agent in water. The reaction proceeded in the manner of living polymerization, suggesting that the number-average molecular weight increased linearly with monomer conversion, whereas the molecular weight distribution remained nearly constant below 1.30, independent of conversion. Poly(methacrylic acid) (PMA) homopolymer was also prepared via RAFT. When aqueous solutions of PSS-PEG-PSS and PMA were mixed below pH 5, watersoluble PSS-PEG-PSS/PMA complexes were formed as a result of hydrogen bonding interactions between the PEG block and the pendant carboxylic acids in PMA. The complex was characterized by 1 H NMR spin-spin relaxation time, light scattering and transmission electron microscopy measurement techniques. The hydrodynamic radius (R h) of the complex depended on the mixing ratio of the PSS-PEG-PSS and PMA molecules. When the mole ratio of ethylene glycol units in PSS-PEG-PSS and the pendant carboxylic acids in PMA was nearly unity, the scattering intensity and R h exhibited maximum values for PSS-PEG-PSS and PMA, which is indicative of stoichiometric complex formation. The complex dissociated at pH greater than 5 because the hydrogen bonding interaction ceased as a result of deprotonation of the pendant carboxylic acids in PMA.

One Pot Doxorubicin Partitioning and Encapsulation on Silica Nanoparticle, Applying Aqueous Two Phase System for Preparation of pH-Responsive Nanocarriers

“…The surface of silica nanoparticles is covered by silanol, which is prone to form hydrogen bondings with PEG and drugs 49,51 . So far, a considerable amount of effort has been devoted to designing pH-sensitive polymeric nanocarriers using hydrogen bonding 49,50,52,53 . Hydrogen-bonded carriers can be used to deliver drugs to tumors that have an acidic environment.…”

pH-Induced Association and Dissociation of Intermolecular Complexes Formed by Hydrogen Bonding between Diblock Copolymers

“…The complex is formed between the two polymers through hydrogen bonding interactions with a stoichiometry of r = 0.6 ( r is the unit molar ratio of PAA/PDEA), and the complex formation depends on pH values. We lately reported [ 12 ] the complex formation behavior of poly(sodium stylenesulfonate)– block– PEG– block– poly(sodium stylenesulfonate) (PNaSS– b –PEG– b –PNaSS) with poly(methacrylic acid) (PMA). Both PNaSS– b– PEG– b –PNaSS and PMA were synthesized via reversible addition–fragmentation chain transfer (RAFT) radical polymerization.…”

Synthesis and Assembly of Designer Styrenic Diblock Polyelectrolytes

“…First, Haladjova et al prepared poly­[oligo­(ethylene glycol) methacrylate]- b -PVBTMA as gene delivery vectors, although the molecular weight distributions of the polymers were not reported. Second, PSS- b -PEO- b -PSS has been synthesized from a bifunctional PEO macro-CTA. , Collectively, these works motivated us to outline a single, systematic protocol for preparing sets of PEO- b -PVBTMA and PEO- b -PSS diblocks as a model synthetic platform for future polyelectrolyte studies.…”

“…Second, PSS-b-PEO-b-PSS has been synthesized from a bifunctional PEO macro-CTA. 37,38 Collectively, these works motivated us to outline a single, systematic protocol for preparing sets of PEO-b-PVBTMA and PEO-b-PSS diblocks as a model synthetic platform for future polyelectrolyte studies.…”