Triterpenoid‐Based Self‐Healing Supramolecular Polymer Hydrogels Formed by Host–Guest Interactions

Abstract

Pentacyclic triterpenoids, a class of naturally bioactive products having multiple functional groups, unique chiral centers, rigid skeletons, and good biocompatibility, are ideal building blocks for fabricating versatile supramolecular structures. In this research, the natural pentacyclic triterpenoid glycyrrhetinic acid (GA) was used as a guest molecule for β-cyclodextrin (β-CD) to form a GA/β-CD (1:1) inclusion complex. By means of GA and β-CD pendant groups in N,N'-dimethylacrylamide copolymers, a supramolecular polymer hydrogel can be physically cross-linked by host-guest interactions between GA and β-CD moieties. Moreover, self-healing of this hydrogel was observed and confirmed by step-strain rheological measurements, whereby the maximum storage modulus occurred at a [GA]/[β-CD] molar ratio of 1:1. Additionally, these polymers displayed outstanding biocompatibility. The introduction of a natural pentacyclic triterpenoid into a hydrogel system not only provides a biocompatible guest-host complementary GA/β-CD pair, but also makes this hydrogel an attractive candidate for tissue engineering.

Thermosensitive Triterpenoid‐Appended Polymers with Broad Temperature Tunability Regulated by Host–Guest Chemistry

“…In our previous study, we reported a 1:1 inclusion complexation of GA with β‐CD (the binding constant K a =1.59×10 3 m −1 ). In addition, the 1 H NMR spectrum further confirmed the complexation of β‐CD with the polymer containing GA pendants.…”

“…Statistical copolymers poly(DMA‐GA‐ x %) ( x =0, 1, 2, 4) bearing GA pendants with different contents were synthesized by means of a free‐radical polymerization of N , N′ ‐dimethylacrylamide (DMA) with GA‐based methacrylate according to our previous work (see the Supporting Information). Their molecular weights, polydispersity indexes (PDIs), and yields are summarized in the Supporting Information.…”

“…Recent studies show GA is an ideal building block for fabricating self‐assembled biocompatible materials because of its rigid skeleton, chiral centers, multiple reactive sites, and good biocompatibility . In our previous work, GA was used as a novel guest molecule to bind β‐CD to form a GA/β‐CD inclusion complex. By incorporating GA and β‐CD pendants into poly( N , N′ ‐dimethylacrylamide), respectively, we obtained two types of copolymers, named poly(DMA‐GA) and poly(DMA‐CD).…”

Blending Electronics with the Human Body: A Pathway toward a Cybernetic Future

“…Liquid alloys composed of gallium are also ideal candidates for creating conductive circuits within elastomeric substrates, which spontaneously can self‐heal electrical and mechanical defects imposed on them during wear and tear . A recent study accomplished this daring task through a simple system composed of a hollow self‐healing polymer (Reverslink@) into which EGaln was injected.…”

Natural Triterpenoid‐ and Oligo(Ethylene Glycol)‐Pendant‐Containing Block and Random Copolymers: Aggregation and pH‐Controlled Release

“…Owing to the biocompatibility, structural rigidity, chirality, self‐assembling capacity, and easy functionalization of hydroxyl and carboxylic groups, GA has served as a useful hydrophobic building block for functional materials . For example, Mezzenga and co‐workers reported that the GA moiety afforded suitable hydrophobic forces for fabricating helical fibers containing three‐folded hybrid nanomaterials of glycyrrhizic acid; our group found that GA pendants in poly(dimethylacrylamide‐ ran ‐GA) could form the host–guest complex with β‐cyclodextrin (β‐CD) in poly(dimethylacrylamide‐ ran ‐CD), thus resulting in a self‐healable polymeric supramolecular hydrogel . Clearly, GA is an ideal choice as the hydrophobic pendant in amphiphilic copolymers.…”