Rapid Ultratough Topological Tissue Adhesives

Abstract

Tissue adhesives capable of achieving strong and tough adhesion in permeable wet environments are useful in many biomedical applications. However, adhesion generated through covalent bond formation directly with the functional groups of tissues (i.e., COOH and NH2 groups in collagen), or using non‐covalent interactions can both be limited by weak, unstable, or slow adhesion. Here, it is shown that by combining pH‐responsive bridging chitosan polymer chains and a tough hydrogel dissipative matrix one can achieve unprecedented ultratough adhesion to tissues (>2000 J m−2) in 5–10 min without covalent bond formation. The strong non‐covalent adhesion is shown to be stable under physiologically relevant conditions and strongly influenced by chitosan molecular weight, molecular weight of polymers in the matrix, and pH. The adhesion mechanism relies primarily on the topological entanglement between the chitosan chains and the permeable adherends. To further expand the applicability of the adhesives, adhesion time can be decreased by dehydrating the hydrogel matrix to facilitate rapid chitosan interpenetration and entanglement (>1000 J m−2 in ≤1 min). The unprecedented adhesive properties presented in this study open opportunities for new strategies in the development of non‐covalent tissue adhesives and numerous bioapplications.

High‐Performance Zinc‐Ion Battery Enabled by Tuning the Terminal Group and Chain Length of PEO‐based Oligomers

“…It is generally believed that the lower the average molecular weight, the lower the viscosity. [12] The viscosity of PEGDME500 with a higher average molecular weight, is much smaller than that of PEG400 and PEGDA400, indicating that PEGDME has less intermolecular interaction. [13] However, when the interaction between oligomer and oligomer is weak, the interaction between water and oligomer is relatively strong, thus breaking the hydrogen bond in water and reducing the activity of water.…”

“…This result shows that the inert end group reduces the viscosity. It is generally believed that the lower the average molecular weight, the lower the viscosity [12] . The viscosity of PEGDME500 with a higher average molecular weight, is much smaller than that of PEG400 and PEGDA400, indicating that PEGDME has less intermolecular interaction [13] .…”

Tough Adhesive Hydrogel for Intraoral Adhesion and Drug Delivery

“…DenTAl may be a promising device for intraoral delivery of small-molecule drugs applicable to the management of painful lesions associated with chronic inflammatory oral conditions. Future studies will examine efficacy of this material in animal models of OLP and RAS, as well as test degradable versions of DenTAl and adhesives based on noncovalent attachment (Freedman et al 2021; Cintron-Cruz et al 2022). Future clinical application of DenTAl may be expanded to local deliveries of antimicrobial and chemotherapeutic agents to treat periodontitis and precancerous or malignant lesions, respectively.…”

Adhesive cryogel particles for bridging confined and irregular tissue defects

“…However, several drawbacks have been highlighted such as lack of biocompatibility (e.g., cyanoacrylate [ 13 – 15 ]) and weak adhesion to tissues (e.g., fibrin [ 16 – 18 ], polyethylene glycol [ 19 , 20 ], nanoparticles [ 21 ], and bioinspired adhesives [ 22 ]). In contrast, adhesive hydrogels have excellent biocompatibility, and exhibit robust adhesion to tissues, controlled drug release, and wound management capabilities [ 23 – 26 ]. However, prefabricated hydrogels have limited applicability for confined and irregular tissue defects [ 27 , 28 ].…”