Hybrid Dry Powders for Rapid Sealing of Gastric Perforations under an Endoscope

Abstract

Effective wound sealing is key to prevent postoperative complications arising from gastric endoscopic submucosal dissection (ESD). Accurate delivery of the adhesive to wet and dynamic tissues and rapid action of the adhesive onsite should be considered for endoscopic operation. A hybrid dry powder (HDP) strategy, characterized by decoupling of powder gelation and tissue adhesion, for rapid sealing of wet tissues is presented. HDPs carrying oppositely charged polyelectrolytes become a hydrogel layer over the target tissue by absorbing the surrounding water and forming strong electrostatic interactions between heterogeneous components. Strong adhesion is realized through hydrogen bonding between the adhesive component, poly(acrylic acid), and the tissue. Wet tissue adhesion can be achieved in a few seconds (adhesion strength of ∼30 kPa to porcine skin). Notably, the HDP-assembled hydrogel can maintain a low swelling rate and resist degradation in acidic aqueous environments (pH 1). Furthermore, HDPs can be delivered to target tissues by spraying via an endoscope. The results of in vivo experiments indicate that healing of gastric ESD perforations by sealing with the powder-assembled hydrogel is as effective as that by sealing with clips. This strategy is expected to facilitate the development of fast-acting hydrogel-based adhesives for endoscopic operation.

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

“…Currently, a wide range of hemostatic powders ranging from inorganic to organic materials, have been extensively researched for their potential in stopping bleeding. ,− For example, zeolite, silicates, or kaolin based inorganic powders are explored to treat with hemorrhage in virtue of their porous hydrophilic structure and inorganic metal oxides . Additionally, natural polymers such as chitosan, cellulose, starch, and alginate have been processed into hemostatic powders, due to their inherent biocompatibility, biodegradability, and a low risk of infection in surgical settings. − The hemostatic mechanism of these traditional hemostatic powders relies on the absorbing blood and concentrating coagulation factors.…”

“…These drawbacks make the hemostatic powders susceptible to being easily dislodged by the force of blood pressure, thereby compromising their hemostatic performance. Recently, self-gelling powders have gained recognition as innovative hemostatic materials due to their ability to combine the advantage of powder (absorbing liquid) and hydrogel (providing excellent mechanical support and wound sealing capabilities). − ,− Thus, several self-gelling powders, such as polyethylenimine/poly­(acrylic acid), poly­(3-[methacryloylamino]-propyltrimethylammonium chloride)/poly­(acrylic acid), chitosan/poly­(acrylic acid), and gelatin/tannic acid/poly­(vinyl alcohol), have been developed and shown to effectively seal and stop bleeding in specific areas. However, these self-gelling powders have limitations in terms of biosafety, biodegradability, and efficient blood clotting.…”

Silk fibroin-based hemostatic powders with instant and robust adhesion performance for sutureless sealing of gastrointestinal defects

“…For example, Guo et al reported hybrid dry powders prepared from acrylic acid and ionic monomers, which assembled into a compact hydrogel layer under water trigger and promoted the stable sealing of gastric perforations. 24 Peng et al reported self-gelling powders prepared from polyethyleneimine and polyacrylic acid that rapidly formed physically cross-linked hydrogels by absorbing water or blood. 25,26 The deposition of self-gelling powders in situ effectively sealed the wounds and stopped acute bleeding.…”

Natural Underwater Bioadhesive Offering Cohesion Modulation via Hydrogen Bond Disruptor: A Highly Injectable and in Vivo Stable Remedy for Gastric Ulcer Resolution

“…However, the nonphysiological gelation conditions may potentially result in additional cytotoxicity. In another study, Guo et al [12] employed rapidly hydrating polyelectrolyte powders for the treatment of gastric perforations, yet the presence of nonbiodegradable components in the formulation could pose a potential obstacle to its formal application. The nonphysiological gelation conditions often yield unsatisfactory outcomes, either with excessively rapid gelation, leading to limited working time and inconvenient surgical operations, or prolonged gelation, resulting in material loss and compromised in vivo stability.…”