Coassembly Modulated pH‐Responsive Hydrogel for Dye Absorption and Release

Abstract

Hydrogel as a carrier for drug delivery system has been developed, but it is hard to change the load and release of drugs through a simple way. Herein, the authors report a novel pH‐sensitive supramolecular binary hydrogel based on Phe‐Gly derivative gelator (LPPG) and 4,4′‐dipyridine disulfide (DPDS). Fourier transform infrared spectroscopy, circular dichroism, and 1H NMR confirm that the driving force for the coassembly process is intermolecular hydrogen bonds. The composite hydrogel can improve the dye adsorption capacity relative to LPPG hydrogel. Moreover, the controllable absorption of the dyes is studied by varying the pH and concentration of dye solutions. LPPG‐DPDS hydrogel can also release of entrapped dyes at physiological pH. The two‐component hydrogel should be a promising system for controllable drug delivery.

Stoichiometry‐Controlled Inversion of Supramolecular Chirality in Nanostructures Co‐assembled with Bipyridines

“…LPPG and DPPG were synthesized through a conventional liquid‐phase reaction according to our previous work (Supporting Information, Figures S1–S6) . DPa, DPe and DPb are commercially available.…”

“…The PPG xerogels showed two clear diffraction peaks, which corresponded to layer spacings of 1.90 and 0.95 nm, based on Bragg's equation; the ratio of 1:1/2 was consistent with an obvious lamellar structure with a d ‐spacing of 1.90 nm . Intermolecular hydrogen bonds between the amide moieties and carboxyl group are the main driving force for the self‐assembly of PPG . Due to the fact that different molecules and complex interactions have been involved in PPG/DPb systems, the SAXRD results are relatively complicated.…”

“…[16] LPPG and DPPG were synthesized through ac onventional liquid-phase reactiona ccording to our previous work (Supporting Information, Figures S1-S6). [17] DPa, DPe and DPb are commerciallya vailable. The self-assemblies of PPG with bipyridines were performed in aqueous solution by ah eating and cooling process.Aracemic mixture of PPGw as not used in this study.…”

“…[21] Intermolecular hydrogen bonds between the amide moieties and carboxyl group are the main driving force for the self-assembly of PPG. [17] Due to the fact that different molecules and complex interactions have been involved in PPG/DPb systems, the SAXRD resultsa re relativelyc omplicated. Well-defined patterns of PPG/DPb = 1:1 xerogels display d-spacings of 2.32 and1 .16 nm (1/2), indicating al amellar structure with al arger d-spacing of 2.32 nm, althought here were maybe not only one layered structure with identicall ayer distance in the sample.…”

Preparation of chitosan and carboxymethylcellulose‐based polyelectrolyte complex hydrogel via SD‐A‐SGT method and its adsorption of anionic and cationic dye

“…Adsorption is one of the most effective and economic ways for the treatment of dye‐containing waste waters . Among various adsorbents, hydrogels exhibit higher performances for dye removals due to their three‐dimensional macromolecular networks of hydrophilic polymers cross‐linked by chemical and/or physical interactions . However, most of the hydrogels reported in literature are for the removal of a specific type of dyes, which limits their application to the treatment of wastewaters containing complex pollutions.…”