Cellulose-based self-healing hydrogel through boronic ester bonds with excellent biocompatibility and conductivity

Abstract

Self-healing hydrogels based on degradable resources have developed rapidly in the past decade due to their extensive bioapplications with biosecurity. In this research, a new kind of cellulose-based selfhealing hydrogel with bio-degradability is constructed through boronic ester linkage. The carboxyethyl cellulose-graft-phenylboronic acid (CMC-B(OH) 2 ) was synthesized through condensation reaction conveniently and then hydrogels were prepared with dynamic boronic ester cross-linking. The chemical structures, microscopic morphologies, mechanical and self-healing properties of the hydrogels were investigated intensively through Fourier transform infrared (FT-IR) spectroscopy, rheological, SEM and tensile testing. The hydrogels formed instantly without any additional catalyst and exhibit excellent selfhealing ability with good mechanical properties. Moreover, the hydrogels were applied for controlled release of doxorubicin (DOX$HCl) and showed a successive slow release profile. Importantly, the hydrogel exhibited excellent biocompatibility and show potential applications in controlled drug delivery, 3D cell culture and tissue engineering.

Soft Materials by Design: Unconventional Polymer Networks Give Extreme Properties

“…For example, polymers modified with boronic acid can form the dynamic boronate ester cross-links with salicyl hydroxamic acid groups in an acidic environment or catechol groups in an alkaline environment. 590,660,666−668 As another example, polyhydroxy polymers such as PVA, 669,670 alginate, 671,672 and cellulose 673 can also be cross-linked into dynamic hydrogels by mixing the polyhydroxy polymers with boronic acid-containing polymers in aqueous solutions. The transient boronate ester networks usually can dynamically restructure after fracture, making the resultant hydrogels injectable and self-healable.…”

“…The boronic acid-containing polymers can react with polymers containing diol functional groups. For example, polymers modified with boronic acid can form the dynamic boronate ester cross-links with salicyl hydroxamic acid groups in an acidic environment or catechol groups in an alkaline environment. ,,− As another example, polyhydroxy polymers such as PVA, , alginate, , and cellulose can also be cross-linked into dynamic hydrogels by mixing the polyhydroxy polymers with boronic acid-containing polymers in aqueous solutions. The transient boronate ester networks usually can dynamically restructure after fracture, making the resultant hydrogels injectable and self-healable. , In addition, the boronate ester cross-linked hydrogels are also glucose-sensitive, because glucose can compete with diol groups to form boronate–glucose complexes and therefore de-cross-link the hydrogels .…”

A Tough and Self-Healing Polymer Enabled by Promoting Bond Exchange in Boronic Esters with Neighboring Hydroxyl Groups

“…Taking advantage of the strong and dynamic boronic ester bonds as cross-linking sites, the resulting dynamic covalent 3OH-PBM polymers not only possess excellent self-healing ability under ambient conditions without any external stimulus (water, heat, light, etc.) but also achieve great mechanical strength and toughness simultaneously, which have never been reported in other relevant literatures (see Figure e, as well as Table S2 in the Supporting Information). ,,− ,,,− …”

Bio-based and bio-inspired adhesives from animals and plants for biomedical applications

“… molecular classes examples from nature adhesives created via a modification of biomolecules Ref. carbohydrates starch, alginate, cellulose, fucoidan, tannic acid, acacia gum, sundew mucilage ( myo -inositol), pollenkit (viscin), propolis propionylated amylose [ 100 ] boronic acid conjugated alginate [ 101 ] cellulose-phenylboronic acid conjugate [ 102 ] alginate crosslinked by organosilane [ 103 ] tannic acid as crosslinker for chitosan [ 104 ] cross-linking by functionalization with methacrylate groups [ 105 ] proteins egg albumen, zein, fibrin, various proteins from mussel, sandcastle worm, frog, salamander, silkworm, starfish, velvet worm, glowworm phenols conjugated with zein [ 106 ] composite of fibrin and hydroxyapatite [ 107 , 108 ] complex formation of DOPA with cations [ 94 ] synthesized structure motifs of sandcastle adhesives [ 109 ] Nb-1R proteins enzymatically cross-linked (frog) [ 110 ] adhesive composed of sericin, gelatine and, carboxymethyl-chitosan [ 111 ] adhesive Sfp1β proteins (starfish) [ 112 ] Glycoproteins from ivy, snail, spider, hagfish, jellyfish collagen-derived scaffold with ivy nanoparticles [ 113 ] snail slime-coated gold nanoparticles [ 114 ] mucin/keratin scaffolds (hagfish) [ 115 ...…”

“…Recently, An et al. [ 102 ] developed such a cellulose-based adhesive hydrogel with self-healing properties. To this aim, a cellulose-phenylboronic acid conjugate was synthesized through a condensation reaction and fabricated hydrogels via dynamic boronic ester cross-linking ( Fig.…”