Wet tissue adhesive hydrogel toughened by wheat gluten.

Tissue adhesives made of natural polymers like protein have good biocompatibility but low adhesion in wet environments. Gluten is a rich naturally occurring protein with a highly soft and stretchable "loop and train" model network. To benefit from this remarkable feature, it was composited with poly(acrylic acid) (PAA) to make a tough double-network wet tissue adhesive hydrogel (G-PAA).

Oppositely charged polysaccharide nanofibers coated gauze with hemostatic potential.

Cotton gauze remains a clinically prevalent hemostatic material, yet its effectiveness remains compromised by bleeding. We have deposited cationic quaternized chitosan (QCS) and anionic catechol-functionalized hyaluronic acid (HADA) nanofibers onto cotton gauze to prepare QCS/HADA@gauze. Upon blood contact, oppositely charged nanofibers electrostatically adhere through complementary charge interactions.

Blood-triggered self-sealing and tissue adhesive hemostatic nanofabric.

Current hemostatic fabric often encounters the issue of blood seeping or leaking through the fabric and at the junctions between the fabric and tissue, leading to extra blood loss. Herein, we report a hemostatic nanofabric composed of anionic and cationic nanofibers. Upon contact with wound, the porous nanofabric can absorb the interfacial blood and self-seal to form a compact physical barrier through interfiber bonding, preventing blood from longitudinally penetrating the fabric.

Unilateral antibacterial Janus hydrogel hemostatic dressing prepared by the dragging effect of a brush.

Hemostasis and subsequent anti-inflammatory measures are essential for wound healing in the human body following trauma or surgical procedures. Here, we try to use the dragging effect of a brush to prepare a Janus hydrogel with the least amount of bacteriostatic agent. The synthesized suspension of polyvinylbenzene-silica@quaternary ammonium salt (PDVB-SiO@NR) Janus particles (JNPs) was selected as ink and brush coated onto one side of a polyacrylic acid (PAA) hydrogel, resulting in Janus hydrogel (JNPs≌PAA).

A tough Janus poly(vinyl alcohol)-based hydrogel for wound closure and anti postoperative adhesion.

Traditional adhesive hydrogels perform well in tissue adhesion but they fail to prevent postoperative tissue adhesion. To address this challenge, a biodegradable Janus adhesive hydrogel (J-AH) was designed and fabricated by the assembly of three different functional layers including anti-adhesive layer, reinforceable layer, and wet tissue adhesive layer. Each layer of J-AH serves a specific function: the top zwitterionic polymeric anti-adhesive layer shows superior resistance to cell/protein and tissue adhesion; the middle poly(vinyl alcohol)/tannic acid reinforceable matrix layer endows the hydrogel with good mechanical toughness of ∼2.

Mussel Foot Protein-Inspired Adhesive Tapes with Tunable Underwater Adhesion.

Instant and strong adhesion to underwater adherends is a big challenge due to the continuous interference of water. Mussel foot protein-bioinspired catechol-based adhesives have garnered great interest in addressing this issue. Herein, a novel self-made catecholic compound with a long aliphatic chain was utilized to prepare thin (∼0.

Amphiphilic Janus cotton gauze with enhanced moisture management and blood coagulation for rapid hemostasis and wound healing.

Cotton gauze is commonly used in initial emergency care. However, its high hydrophilicity and limited clotting capacity can lead to the excessive absorption of blood, resulting in unnecessary blood loss. Herein, an amphiphilic Janus cotton gauze with excellent moisture management and enhanced blood coagulation has been developed via in situ generating bioactive glass (BG) onto the cotton gauze (CG), and then attaching cardanol (CA) onto one side of the BG-loaded CG (CG@BG) via click reaction.

Coagulating blood into adhesive gel by hybrid powder based on oppositely charged polysaccharide/tannic acid-modified mesoporous bioactive glass.

Hemostatic powder is widely utilized in emergency situations to control bleeding due to its ability to work well on wounds with irregular shapes, ease of application, and long-term stability. However, traditional powder often suffers from limited tissue adhesion and insufficient support for blood clot formation, leaving it susceptible to displacement by the flow of blood. This study introduces a hemostatic powder composed of tannic modified mesoporous bioactive glass (TMBG), cationic quaternized chitosan (QCS), and anionic hyaluronic acid modified with catechol group (HADA).

Clotting Blood into an Adhesive Gel by Hemostatic Powder Based on Cationic/Anionic Polysaccharides and Laponite.

Hemostatic powder is widely employed for emergency bleeding control due to its ability to conform to irregularly shaped wounds, ease of use, and stable storage. However, current powders exhibit limited tissue adhesion and insufficient support for thrombus formation, making them easily washed away by blood. In this study, a hybrid powder (QAL) was produced by mixing quaternized chitosan (QCS) powder, catechol-modified alginate (Cat-SA) powder, and laponite (Lap) powder.

Gluing blood into adhesive gel by oppositely charged polysaccharide dry powder inspired by fibrin fibers coagulation mediator.

Hemostatic powders that adapt to irregularly shaped wounds, allowing for easy application and stable storage, have gained popularity for first-aid hemorrhage control. However, traditional powders often provide weak thrombus support and exhibit limited tissue adhesion, making them susceptible to dislodgment by the bloodstream. Inspired by fibrin fibers coagulation mediator, we have developed a bi-component hemostatic powder composed of positively charged quaternized chitosan (QCS) and negatively charged catechol-modified alginate (Cat-SA).

Ferried Albumin-Inspired Bioadhesive With Dynamic Interfacial Bonds for Emergency Rescue.

Emergency prehospital wound closure and hemorrhage control are the first priorities for life-saving. Majority of bioadhesives form bonds with tissues through irreversible cross-linking, and the remobilization of misalignment may cause severe secondary damage to tissues. Therefore, developing an adhesive that can quickly and tolerably adhere to traumatized dynamic tissue or organ surfaces in emergency situations is a major challenge.

Cohering Plasma into Adhesive Gel by Natural Biopolymer-Nanoparticle Hybrid Powder for Efficient Hemostasis and Wound Healing.

Hemostatic powder is commonly used in emergency bleeding control due to its suitability for irregularly shaped wounds, ease of use, and stable storage. However, traditional powder often has limited tissue adhesion and weak thrombus support, which makes it vulnerable to displacement by blood flow. Herein, we have developed a tricomponent hemostatic powder (MQS) composed of mesoporous bioactive glass nanoparticle (MBG), positively charged quaternized chitosan (QCS), and negatively charged catechol-modified alginate (SADA).

Robust but On-Demand Detachable Wet Tissue Adhesive Hydrogel Enhanced with Modified Tannic Acid.

Adhesives with robust but readily detachable wet tissue adhesion are of great significance for wound closure. Polyelectrolyte complex adhesive (PECA) is an important wet tissue adhesive. However, its relatively weak cohesive and adhesive strength cannot satisfy clinical applications.

Tough and On-Demand Detachable Wet Tissue Adhesive Hydrogel Made from Catechol Derivatives with a Long Aliphatic Side Chain.

Wet adhesion is critical in cases of wound closure, but it is usually deterred by the hydration layer on tissues. Inspired by dopamine-mediated underwater adhesion in mussel foot proteins, wet tissue adhesives containing catechol with 2-3 carbons side chains are reported mostly. To make wet adhesion of this type of adhesives much tougher, catechol derivatives with a long aliphatic side chain (≈10 atoms length) are synthesized.

Polysaccharides based rapid self-crosslinking and wet tissue adhesive hemostatic powders for effective hemostasis.

Hemostatic powders with flexible shape are widely used for the noncompressible and inaccessible hemorrhage wounds. However, current hemostatic powders display poor wet tissue adhesion and fragile mechanical strength of the powder-supported blood clots, leading to compromised hemostasis efficacy. Herein, a bi-component of carboxymethyl chitosan (CMCS) and aldehyde-modified hyaluronic acid grafted with catechol groups (COHA) was designed.

Mussel Foot Protein Inspired Tape-Type Adhesive with Water-Responsive, High Conformal, Tough, and On-Demand Detachable Adhesion to Wet Tissue.

Wet adhesion is highly demanded in noninvasive wound closure, tissue repair, and biomedical devices, but it is still a big challenge for developing biosafe and tough wet bioadhesives due to low or even nonadhesion in the wet state for conventional adhesives. Inspired by the wet-adhesion-contributing factors of mussel foot proteins, a water-responsive dry robust tissue adhesive PAGU tape is made with thickness of <0.5 mm through fast UV-initiated copolymerization of acrylic acid (AA), gelatin (Gel), and hexadecenyl-1,2-catechol (UH).

Chitin-glucan composite sponge hemostat with rapid shape-memory from Pleurotus eryngii for puncture wound.

Efficient hemostasis is a great challenge for treating the inaccessible hemorrhage wounds. A novel shape-memory chitin-glucan hemostatic sponge (ATC-Sponge) is constructed via sequentially in-situ removal of protein and glucan from Pleurotus eryngii fruiting body, TEMPO oxidation and Ca crosslinking. The sponge displays interconnected microporous structure with high water absorption and robust mechanical properties.

Bischler-Napieralski Synthesis of Polycyclic N-Heteroaromatics Based on TfO-Promoted Electrophilic Activation of -Aryl-2-Propynamides.

2-Propynamides have been never used as substrates in classic and TfO-promoted Bischler-Napieralski reactions. In this article, a novel tandem synthesis of benzo[]acridines is developed from -aryl-2-propynamides and alkynes consisting of a TfO-promoted intermolecular Bischler-Napieralski reaction and a TfOH-promoted intramolecular Friedel-Crafts reaction.

Efficient, biosafe and tissue adhesive hemostatic cotton gauze with controlled balance of hydrophilicity and hydrophobicity.

Cotton gauze is a widely used topical hemostatic material for bleeding control, but its high blood absorption capacity tends to cause extra blood loss. Therefore, development of rapid hemostatic cotton gauze with less blood loss is of great significance. Here, we develop an efficient hemostatic cotton gauze whose surface is slightly modified with a catechol compound which features a flexible long hydrophobic alkyl chain terminated with a catechol group.

Tandem Synthesis of 1,3-Disubstituted Naphthalenes via TfOH-Promoted Directed-Aldol and Friedel-Crafts Reactions.

A TfOH-promoted tandem synthesis of 1,3-disubstituted naphthalenes is developed via a directed-aldol reaction and a Friedel-Crafts reaction. Two new C-C bonds and one new benzene ring are created efficiently in one pot due to the discovery of a TfOH-promoted highly chemoselective directed-aldol reaction between two different ketones with α-hydrogens.

Bischler-Napieralski Synthesis of 6-Alkynyl Phenanthridines Based on TfO-Promoted Electrophilic Activation of -Aryl-2-propynamides.

An efficient method for the synthesis of 6-alkynyl phenanthridines was developed. The method offered the first example to use 2-propynamides as substrates in the Bischler-Napieralski reaction and to create alkynylnitrilium triflates as new active intermediates in organic synthesis.

General Synthesis of Fully Substituted 4-Aminooxazoles from Amides and 1,4,2-Dioxazol-5-ones Based on Amide Activation and Umpolung Process.

A general and efficient synthesis of fully substituted 4-aminodixazoles was developed based on the strategies of amide activation and umpolung reaction. In this method, 1,4,2-dioxazol-5-ones were introduced as a rare type of umpolung reagent bearing a nucleophilic -atom that could be used well together with the activating agent TfO. Because 1,4,2-dioxazol-5-ones played triple roles as an umpolung reagent, a substrate, and a weak base, the method proceeded smoothly under extremely convenient conditions.

General Synthesis of α-Alkyl Ynones from Morpholine Amides and 1-Copper(I) Alkynes Promoted by Triflic Anhydride.

The first general method for the synthesis of α-alkyl ynones was developed based on the strategy of electrophilic activation of amides. Its distinctive advantages are attributed to the use of air-stable "bare" 1-copper(I) alkyne as a mild nucleophile without any exogeneous ligand.

Carboxy Group as a Remote and Selective Chelating Group for C-H Activation of Arenes.

The first example of carboxy group assisted, remote-selective C(sp )-H activation with a Pd catalyst has been developed and proceeds through a possible κ coordination of the carboxy group, thus suppressing the ortho-C-H activation through κ coordination. Besides meta-C-H olefination, direct meta-arylation of hydrocinnamic acid derivatives with low-cost aryl iodides has been achieved for the first time. These findings may motivate the exploration of novel reactivities of the carboxy assisted C-H activation reactions with intriguing selectivities.