Commercial or clinical
tissue adhesives are currently limited due
to their weak bonding strength on wet biological tissue surface, low
biological compatibility, and slow adhesion formation. Although catechol-modified
hyaluronic acid (HA) adhesives are developed, they suffer from limitations:
insufficient adhesiveness and overfast degradation, attributed to
low substitution of catechol groups. In this study, we demonstrate
a simple and efficient strategy to prepare mussel-inspired HA hydrogel
adhesives with improved degree of substitution of catechol groups.
Because of the significantly increased grafting ratio of catechol
groups, dopamine-conjugated dialdehyde–HA (DAHA) hydrogels
exhibit excellent tissue adhesion performance (i.e., adhesive strength
of 90.0 ± 6.7 kPa), which are significantly higher than those
found in dopamine-conjugated HA hydrogels (∼10 kPa), photo-cross-linkable
HA hydrogels (∼13 kPa), or commercially available fibrin glues
(2–40 kPa). At the same time, their maximum adhesion energy
is 384.6 ± 26.0 J m–2, which also is 40–400-fold,
2–40-fold, and ∼8-fold higher than those of the mussel-based
adhesive, cyanoacrylate, and fibrin glues, respectively. Moreover,
the hydrogels can gel rapidly within 60 s and have a tunable degradation
suitable for tissue regeneration. Together with their cytocompatibility
and good cell adhesion, they are promising materials as new biological
adhesives.
In this study, dynamic
imine covalent bonds were introduced into
vanillin-based vitrimers networks, endowing thermosets with hot-reprocessing
ability and chemical recyclability under acid hydrolysis. First, dialdehyde
monomer, which was synthesized from lignin-derived vanillin monomer,
was reacted with conventional amine cross-linkers to form dynamic
imine bond networks. Even after three hot-processing cycles, the tensile
strength and elongation at break of polyschiff vitrimers could be
recovered at least up to 71.2 and 72.8%, respectively, through the
imine metathesis reaction. Importantly, the dialdehyde monomers showed
enhanced recyclability under strong acid solution and could be reused
to regenerate polyschiff vitrimers. These characteristics of reprocessablility,
recyclablility, and biobased monomer present a feasible way to satisfy
the demands of sustainability.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.