Adhesive, Antibacterial, Conductive, Anti-UV, Self-Healing, and Tough Collagen-Based Hydrogels from a Pyrogallol-Ag Self-Catalysis System

Abstract

Recently, versatile hydrogels with multifunctionality have been widely developed with emerging applications as wearable and implantable devices. In this work, we reported novel versatile hydrogels by self-catalyzing the gelation of an interpenetrating polymer network consisting of acrylic acid (AA) monomers and GA-modified collagen (GCOL) in situ decorated silver nanoparticles (AgNPs). The resultant hydrogel, namely AgNP@GCOL/PAA, has many desirable features, including good mechanical properties (such as 123 kPa, 916%, and 1961 J m−2 for the fracture stress, strain and tearing energy) that match with those of animal skin, excellent self-healing performance, favorable conductivity and strain sensitivity as a flexible biosensor, and excellent antibacterial and anti-UV properties, as well as the strong adhesiveness on skin. Moreover, AgNP@GCOL/PAA showed excellent biocompatibility via in vitro cell culture. Remarkably, AgNP@GCOL/PAA displayed superior hemostatic properties with sharply decreasing blood loss for a mouse liver incision, closely related to its strong self-adhesion which produced anchoring strength to the bleeding site and thus formed a network barrier with liver tissue. This study provides new opportunities for the facile preparation of widely used multifunctional collagen-based hydrogels based on a simple pyrogallol-Ag system.

A physicochemical double-cross-linked gelatin hydrogel with enhanced antibacterial and anti-inflammatory capabilities for improving wound healing

“…The self-healing behavior was then measured using the Tsg-THA&Fe40, by means of a variable strain scan test (HAAKE™ MARS™ 40) at an angular frequency (1 rad s −1 ). The strain was changed from a low strain (1.0%, 60 s) to a high strain (500%, 60 s), and five cycles were performed [ 42 ]. Macroscopic autonomous healing tests were performed to assess the healing capacity of the Tsg-THA&Fe hydrogel.…”

Advances in the Translation of Electrochemical Hydrogel‐Based Sensors

“…[154] Similarly, Zhang et al proposed a method of interpenetrating the PAA hydrogel network with AgNPs which displayed excellent biocompatibility, skin-like mechanical properties (e.g., fracture stress: 123 kPa, strain: 916%, tearing energy: 1961 J m −2 ), and most importantly served as a means for superior hemostasis stemming from high adhesion between the hydrogel and the desired tissue. [155] The adhesion was assessed using the lap-shear strength test between porcine tissue to mimic human skin; it was repeated over other materials like bone, rubber, glass, metal, and plastic, yielding high adhesion likely due to the presence of phenolic hydroxyl groups that are more drawn outward in the presence of a highly moist environment. [155] Over time, the moisture is likely reduced, resulting in weakened adhesion.…”

“…[ 155 ] The adhesion was assessed using the lap‐shear strength test between porcine tissue to mimic human skin; it was repeated over other materials like bone, rubber, glass, metal, and plastic, yielding high adhesion likely due to the presence of phenolic hydroxyl groups that are more drawn outward in the presence of a highly moist environment. [ 155 ] Over time, the moisture is likely reduced, resulting in weakened adhesion. Furthermore, the presence of π – π and π –cation interactions of the benzene rings as well as the hydrogen bond formation at the terminal hydroxy functional groups of the phenolic hydroxyl groups promote bioadhesion between the PAA hydrogel and the amino groups in tissue.…”

“…Furthermore, the presence of π – π and π –cation interactions of the benzene rings as well as the hydrogen bond formation at the terminal hydroxy functional groups of the phenolic hydroxyl groups promote bioadhesion between the PAA hydrogel and the amino groups in tissue. [ 155 ] Nonchemical adhesion was proposed by Singh et al. who designed “voltaglue,” a method based on voltage‐cured bioadhesives that was gelled in 60 s while maintaining skin‐like modulus.…”

“…Furthermore, the presence of 𝜋-𝜋 and 𝜋-cation interactions of the benzene rings as well as the hydrogen bond formation at the terminal hydroxy functional groups of the phenolic hydroxyl groups promote bioadhesion between the PAA hydrogel and the amino groups in tissue. [155] Nonchemical adhesion was proposed by Singh et al who designed "voltaglue," a method based on voltage-cured bioadhesives that was gelled in 60 s while maintaining skin-like modulus. The adhesion strength was evaluated by the lap-shear test on swine aortic tissue to yield similarly pseudoplastic levels of strength and stretchability in a moist environment coated in varied concentrations of PBS, thereby providing a biocompatible alternative to classical sutures and staples that can be a source of wound infection.…”