Preparation and pH‐Dependent Properties of Hydrogels Based on Acidic Copolymers with PEG Side Chains and α‐Cyclodextrin

Abstract

A variety of differently structured PEG‐based polymers can form physically cross‐linked PEG hydrogels with α‐cyclodextrin. The polymer structures strongly influence the properties of the hydrogel and its formation. Four different copolymers of methoxy PEG methacrylate and methacrylic acid are used together with α‐cyclodextrin to study hydrogel formation speed and gel strength. The hydrogels are formed within 1–25 min, and the formation process is examined in situ by dynamic light scattering. The gel formation time is pH dependent due to the methacrylic acid present in the polymers. The gel strength examined by texture analyzer also depends on the composition and pH. With prior mechanical destruction, all hydrogels are dissolvable in an excess of water, being a useful feature for an in vivo usage. By analyzing the structures of the hydrogels with confocal light microscopy (laser scanning confocal microscopy) and scanning electron microscope (SEM) after freeze etching, the different hydrogel structures can be observed.

Injectable thermogel constructed from self-assembled polyurethane micelle networks for 3D cell culture and wound treatment

“…Consequently, the balance between hydrophilic and hydrophobic interactions of the segments in WPU, as well as pendant PEG bridging/entanglement, collectively influenced the self-assembly behavior and overall performance of the emulsions. 37,38 This ultimately leads to particle aggregation and the formation of hydrogels. This observation aligns with the gel temperature measurements obtained through rheology.…”

α-Cyclodextrin-Based Polypseudorotaxane Hydrogels

“…PEG chains were grafted onto chitosan [135], hyaluronic acid [136], glucomannan [137], alginate [138], and heparin [139], and various factors affected the gelation properties of the resulting materials, including the substrate ratio and concentration, temperature, pH, and grafted PEG content. Very recently, Hartwig et al [132] studied the kinetics of supramolecular hydrogel formation and the mechanical properties resulting from structural changes of the polymer. For this study, a PPR/α-CD hydrogel that was based on acidic copolymers with PEG side chains made of methoxy-PEG methacrylate and methacrylic acid (MA) was prepared.…”