Polymer Architecture Effects on Poly(N,N‐Diethyl Acrylamide)‐b‐Poly(Ethylene Glycol)‐b‐Poly(N,N‐Diethyl Acrylamide) Thermoreversible Gels and Their Evaluation as a Healthcare Material

Abstract

Thermoreversible gels which transition between liquid‐like and solid‐like states when warmed have enabled significant novel healthcare technologies. Poly(N,N‐diethyl acrylamide) (PDEA) is a thermoresponsive polymer which can be used as a trigger to form thermoreversible gels, however its use in these materials is limited and crucial design principles are unknown. Herein ABA copolymers with the structure PDEA‐b‐poly(ethylene glycol) (PEG)‐b‐PDEA are synthesized to give four block copolymers with varied molecular weight of PDEA and PEG blocks. Rheometry on solutions of the block copolymers reveals that high molecular weight PEG blocks are required to form thermoreversible gels with predominantly solid‐like behavior. Furthermore, small‐angle X‐ray scattering elucidates clear differences in the nanostructure of the copolymer library which can be linked to distinct rheological behaviors. A thermoreversible gel formulation based on PDEA (20 kDa)‐b‐PEG (10 kDa)‐b‐PDEA (20 kDa) is designed by optimizing the polymer concentration and ionic strength. It is found that the gel is mucoadhesive, stable, and non‐toxic, as well as giving controlled release of a hydrophobic drug. Overall, this study provides insight into the effect of polymer architecture on the nanostructure and rheology of PDEA‐b‐PEG‐b‐PDEA and presents the development of a highly functional thermoreversible gel with high promise for healthcare applications.

Hydrogels with Reversible Crosslinks for Improved Localised Stem Cell Retention: A Review

“…Cytotoxicity measurements on human keratinocyte (HaCaT) cells were accomplished with either an MTS assay, measuring mitochondrial activity, and an LDH assay to determine the porosity of the cell membrane. Considering that the dosing interval was short (2 h), the results provided preliminary reassurance that the materials could be used in cell‐based applications [115] …”

“…Considering that the dosing interval was short (2 h), the results provided preliminary reassurance that the materials could be used in cell-based applications. [115] In the work of Fan et al polymerization of acrylamide in the presence of tannic Acid (TA), and kaolin (KA) produced hydrogels with strong mechanical properties, high adhesion strength, and hemostatic efficiency. In the hydrogels, TA was applied as a chemical crosslinker and for wet adhesion via the catechol groups, while KA was used as a physical crosslinker and for haemostatic acceleration.…”

Structure–gelation property relationships of phenolic glycosides of pentose sugars: pH dependent controlled release of curcumin

“…Therefore, the release can also be explained by the zero-order kinetics model if we ignore the initial 20 h of the release during which time the actual release was very low. 50 Such a release may be associated with the stability of the gel with respect to time. Initially, the gel was stable and the release was very slow.…”

Enhancing Mucoadhesive Properties of Gelatin through Chemical Modification with Unsaturated Anhydrides

“…Experiments to evaluate the mucosal retention of modified and unmodified gelatin-based formulations on ex vivo porcine vaginal and sheep nasal tissues were conducted using a well-established flow-through method involving fluorescent detection with minor modifications. ,− Initially, freshly excised vaginal or nasal tissue was mounted on a microscope glass slide with the mucosal side facing upward, then placed on a substrate fixed at an angle of 20° and prerinsed with 1 mL of either VFS or ANF solution, respectively, before commencing each ex vivo mucoadhesion test.…”