Adhesive cryogel particles for bridging confined and irregular tissue defects.

BACKGROUND: Reconstruction of damaged tissues requires both surface hemostasis and tissue bridging. Tissues with damage resulting from physical trauma or surgical treatments may have arbitrary surface topographies, making tissue bridging challenging. METHODS: This study proposes a tissue adhesive in the form of adhesive cryogel particles (ACPs) made from chitosan, acrylic acid, 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The adhesion performance was examined by the 180-degree peel test to a collection of tissues including porcine heart, intestine, liver, muscle, and stomach. Cytotoxicity of ACPs was evaluated by cell proliferation of human normal liver cells (LO2) and human intestinal epithelial cells (Caco-2). The degree of inflammation and biodegradability were examined in dorsal subcutaneous rat models. The ability of ACPs to bridge irregular tissue defects was assessed using porcine heart, liver, and kidney as the ex vivo models. Furthermore, a model of repairing liver rupture in rats and an intestinal anastomosis in rabbits were established to verify the effectiveness, biocompatibility, and applicability in clinical surgery. RESULTS: ACPs are applicable to confined and irregular tissue defects, such as deep herringbone grooves in the parenchyma organs and annular sections in the cavernous organs. ACPs formed tough adhesion between tissues [(670.9 ± 50.1) J/m2 for the heart, (607.6 ± 30.0) J/m2 for the intestine, (473.7 ± 37.0) J/m2 for the liver, (186.1 ± 13.3) J/m2 for muscle, and (579.3 ± 32.3) J/m2 for the stomach]. ACPs showed considerable cytocompatibility in vitro study, with a high level of cell viability for 3 d [(98.8 ± 1.2) % for LO2 and (98.3 ± 1.6) % for Caco-2]. It has comparable inflammation repair in a ruptured rat liver (P = 0.58 compared with suture closure), the same with intestinal anastomosis in rabbits (P = 0.40 compared with suture anastomosis). Additionally, ACPs-based intestinal anastomosis (less than 30 s) was remarkably faster than the conventional suturing process (more than 10 min). When ACPs degrade after surgery, the tissues heal across the adhesion interface. CONCLUSIONS: ACPs are promising as the adhesive for clinical operations and battlefield rescue, with the capability to bridge irregular tissue defects rapidly.

Injectable and tissue adhesive EGCG-laden hyaluronic acid hydrogel depot for treating oxidative stress and inflammation.

Oxidative stress and inflammation are common pathological mechanisms for the progression of tissue degeneration. Epigallocatechin-3-gallate (EGCG) features antioxidant and anti-inflammatory properties, which is a promising drug for the treatment of tissue degeneration. Herein, we utilize the phenylborate ester reaction of EGCG and phenylboronic acid (PBA) to fabricate an injectable and tissue adhesive EGCG-laden hydrogel depot (EGCG HYPOT), which can achieve anti-inflammatory and antioxidative effects via smart delivery of EGCG. Specifically, the phenylborate ester bonds, formed by EGCG and PBA-modified methacrylated hyaluronic acid (HAMA-PBA), endow EGCG HYPOT injectability, shape adaptation and efficient load of EGCG. After photo-crosslinking, EGCG HYPOT exhibits good mechanical properties, tissue adhesion and sustained acid-responsive release of EGCG. EGCG HYPOT can scavenge oxygen and nitrogen free radicals. Meanwhile, EGCG HYPOT can scavenge intracellular reactive oxygen species (ROS) and suppress the expression of pro-inflammatory factors. EGCG HYPOT may provide a new idea for alleviation of inflammatory disturbance.

Comparison of Tissue Adhesive Glue with Subcuticular Absorbable Suture for Skin Closure Following Thyroid Surgery: A single-blinded randomised controlled trial.

Objectives: This study aimed to compare the skin closure time, postoperative pain and the scar outcome between tissue adhesive and sub-cuticular sutures in thyroid surgery. Methods: This study was conducted in Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, a tertiary care hospital in India from March 2017 to December 2019. Adult patients undergoing thyroid surgery were included while those with previous neck surgery, history of keloids/hypertrophic scars and those undergoing concomitant neck dissections were excluded. Following platysma closure, patients were randomised into two groups (tissue adhesive and subcuticular sutures) using the Serially Numbered Opaque Sealed Envelopes technique. A sample size of 64 in each group was calculated for this prospective, single-blinded and randomised controlled trial. The primary outcome was the skin closure time. The secondary outcomes were postoperative pain at 24 hours and scar scoring at 1st and 3rd postoperative month. Statistical analysis was done using SPSS software. Results: A total sample of 124 patients were included in this study, with 61 patients assigned to the suture group and 63 assigned to the tissue adhesive group. The median skin closure time and postoperative pain was significantly lower in the tissue adhesive group as compared to the suture group (P <0.01). There was no statistically significant difference in scar outcome at the 1st or 3rd months between both groups (P = 0.088 and 0.137, respectively). There were no wound-related complications in either group. When a subgroup analysis was conducted, no difference was seen in the scar outcome or wound-related complications in patients with comorbidities. There were no instances of allergic contact dermatitis to the tissue adhesive. Conclusion: The use of tissue adhesive leads to lower operative time and less postoperative pain in thyroid surgeries. The scar outcome is comparable between tissue adhesives and subcuticular sutures.

Circumcision wound dressing with octylcyanoacrylate tissue adhesive.

OBJECTIVE: Circumcision wounds are commonly dressed with paraffin gauze dressings. Octylcyanoacrylate tissue adhesive (Dermabond; Ethicon, US) is increasingly being used for wound closure, as well as wound dressing. This study compared the outcomes of tissue adhesive dressing versus paraffin gauze dressing for circumcision wounds. METHOD: Adult male patients undergoing circumcision were randomised into two groups: tissue adhesive dressing (study group) or paraffin gauze dressing (control group). They were followed up at two weeks and at two months after surgery. The primary objective of this study was to determine the difference in patient-reported dressing satisfaction at two week follow-up. Our secondary outcomes included operation time, postoperative pain, postoperative complications, patient-reported cosmetic satisfaction, surgeon-reported cosmetic satisfaction, and surgeon-reported objective measure of cosmetic outcome using a validated scale. RESULTS: A cohort of 40 patients was randomised into two equal groups, study and control. Tissue adhesive dressing was associated with a significantly better patient-reported dressing satisfaction, with a mean Likert scale score of 4.53±0.51 for the study group versus 3.20±1.24 for the control group (p<0.001). It was also associated with a significantly better patient-reported cosmetic satisfaction of 4.58±0.51 versus 4.00±1.12 (p<0.05), respectively. There was no difference in operation time, postoperative pain, postoperative complications or surgeon-reported cosmetic outcomes. CONCLUSION: Tissue adhesive dressing is an acceptable alternative to paraffin gauze dressing for circumcision wounds. This option should be offered to all patients undergoing circumcision.

A natural biological adhesive from snail mucus for wound repair.

The discovery of natural adhesion phenomena and mechanisms has advanced the development of a new generation of tissue adhesives in recent decades. In this study, we develop a natural biological adhesive from snail mucus gel, which consists a network of positively charged protein and polyanionic glycosaminoglycan. The malleable bulk adhesive matrix can adhere to wet tissue through multiple interactions. The biomaterial exhibits excellent haemostatic activity, biocompatibility and biodegradability, and it is effective in accelerating the healing of full-thickness skin wounds in both normal and diabetic male rats. Further mechanistic study shows it effectively promotes the polarization of macrophages towards the anti-inflammatory phenotype, alleviates inflammation in chronic wounds, and significantly improves epithelial regeneration and angiogenesis. Its abundant heparin-like glycosaminoglycan component is the main active ingredient. These findings provide theoretical and material insights into bio-inspired tissue adhesives and bioengineered scaffold designs.

Injectable Tissue-Adhesive Hydrogel for Photothermal/Chemodynamic Synergistic Antibacterial and Wound Healing Promotion.

It is an exigent need for the development of hydrogel dressings with desirable injectability, good adhesive, antibacterial, and wound healing promotion properties. Herein, the multifunctional injectable hydrogels with good tissue adhesion are designed based on Ag-doped Mo2C-derived polyoxometalate (AgPOM) nanoparticles, urea, gelatin, and tea polyphenols (TPs) for antibacterial and wound healing acceleration. After being injected into the tissue, urea diffuses out under the concentration gradient, and TPs and gelatin chains recombine to trigger the in situ formation of hydrogel with excellent adhesiveness. AgPOM fixed in the hydrogel could not only react with hydrogen peroxide in the infection site to generate singlet oxygen to kill the bacteria but also convert near-infrared light into heat under 1060 nm laser irradiation to realize sterilization. In vitro studies display the high bactericidal ability of the hydrogel against drug-resistant Staphylococcus aureus and also exhibit a prominent therapeutic effect on infected wounds through synergistic photothermal/chemodynamic therapy and accelerate wound healing. Hence, the injectable hydrogel with AgPOM as the antimicrobial agent can be a novel therapeutic agent for drug-resistant bacteria-infected wounds and wound healing promotion.

Ultra-soft and highly stretchable tissue-adhesive hydrogel based multifunctional implantable sensor for monitoring of overactive bladder.

A highly stretchable and tissue-adhesive multifunctional sensor based on structurally engineered islets embedded in ultra-soft hydrogel is reported for monitoring of bladder activity in overactive bladder (OAB) induced rat and anesthetized pig. The use of hydrogel yielded a much lower sensor modulus (1 kPa) compared to that of the bladder (300 kPa), while the strong adhesiveness of the hydrogel (adhesive strength: 260.86 N/m) allowed firm attachment onto the bladder. The change in resistance of printed liquid metal particle thin-film lines under strain were used to detect bladder inflation and deflation; due to the high stretchability and reliability of the lines, surface strains of 200% could be measured repeatedly. Au electrodes coated with Platinum black were used to detect electromyography (EMG). These electrodes were placed on structurally engineered rigid islets so that no interfacial fracture occurs under high strains associated with bladder expansion. On the OAB induced rat, stronger signals (change in resistance and EMG root-mean-square) were detected near intra-bladder pressure maxima, thus showing correlation to bladder activity. Moreover, using robot-assisted laparoscopic surgery, the sensor was placed onto the bladder of an anesthetized pig. Under voiding and filling, bladder strain and EMG were once again monitored. These results confirm that our proposed sensor is a highly feasible, clinically relevant implantable device for continuous monitoring OAB for diagnosis and treatment.

Dual crosslinked injectable protein-based hydrogels with cell anti-adhesive properties.

Currently, one of the most severe clinical concerns is post-surgical tissue adhesions. Using films or hydrogel to separate the injured tissue from surrounding tissues has proven the most effective method for minimizing adhesions. Therefore, by combining dual crosslinking with calcium ions (Ca2+) and tetrakis(hydroxymethyl) phosphonium chloride, we were able to create a novel, stable, robust, and injectable dual crosslinking hydrogel using albumin (BSA). This dual crosslinking has preserved the microstructure of the hydrogel network during the degradation process, which contributes to the hydrogel's mechanical strength and stability in a physiological situation. At 60% strain, compressive stress was 48.81 kPa obtained. It also demonstrated excellent self-healing characteristics (within 25 min), tissue adhesion, excellent cytocompatibility, and a quick gelling time of 27 ± 6 s. Based on these features, the dual crosslinked injectable hydrogels might find exciting applications in biomedicine, particularly for preventing post-surgical adhesions.

Synthesis and characterization of mussel-inspired nanocomposites based on dopamine-chitosan-iron oxide for wound healing: In vitro study.

There are many challenges faced the soft tissue adhesives in the medical application field. For example, there is a limited effective binding between the medical adhesive and different types of soft tissues. Chitosan (CS) and dopamine (DA) were used as structural units for synthesizing nanocomposites utilized as a wet tissue adhesive. To produce dopamine-chitosan-iron oxide nanocomposites (DA-CS-Fe3O4 NCs), DA was loaded onto chitosan-iron oxide nanocomposites. The nanocomposites have been prepared using ionic gelation method under vigorous homogenization and characterized by different techniques. Fourier-transform infrared spectroscopy (FTIR) have shown that DA-CS- Fe3O4 NCs could attach to the tissue through two possible functional groups, namely, the catechol and amine groups. The results of in vitro scratch wound-healing assay suggested that the prepared DA-CS- Fe3O4 NCs facilitate cell migration (the wound-closure percentage reached 96% at 72 h). All experimental results confirm that DA-CS- Fe3O4 NCs are strongly recommended for use as a soft medical tissue adhesive in wound healing and surgeries such as vascular surgery. In addition, the results of the whole blood clotting, antibacterial assessment, live and dead assay, cytotoxicity test, and wound-healing assay indicate that DA-CS-Fe3O4 NCs can be used as a multifunctional biomedical adhesive.

Silk Fibroin-Based Tough Hydrogels with Strong Underwater Adhesion for Fast Hemostasis and Wound Sealing.

Rapid and strong adhesion of hydrogel adhesives is required for instant wound closure and hemostasis. However, in situ hydrogel formation and sufficient adhesion at target tissue sites in biological environments are severely compromised by the presence of blood and body fluids. In this work, an underwater adhesive hydrogel (named SHCa) is fabricated with rapid in situ gelation, enhanced mechanical toughness, and robust underwater adhesion. The SHCa can undergo rapid UV irradiation-induced gelation under water within 5 s and adhere firmly to underwater surfaces for 6 months. The synergistic effects of crystalline ß-sheet structures and dynamic energy-dissipating mechanisms enhance the mechanical toughness and cohesion, supporting the balance between adhesion and cohesion in wet environments. Importantly, the SHCa can achieve rapid in situ gelation and robust underwater adhesion at various tissue surfaces in highly dynamic fluid environments, substantially outperforming the commercially available tissue adhesives. The lap shear adhesion strength and wound closure strength of SHCa on blood-covered substrates are 7.24 and 12.68 times higher than those of cyanoacrylate glue, respectively. Its fast hemostasis and wound sealing performance are further demonstrated in in vivo animal models. The proposed hydrogel with strong underwater adhesion provides an effective tool for fast wound closure and hemostasis.

Wound closure with a mesh and liquid tissue adhesive (Dermabond Prineo) system in pediatric spine surgery: a prospective single-center cohort study incorporating parent-reported outcome measures.

OBJECTIVE: Wound healing can be challenging in children undergoing spine surgery for neurological conditions due to a high risk of cerebrospinal fluid (CSF) leakage and wound infection. In adults, use of the Dermabond Prineo (DP) skin closure system, which consists of both tissue adhesive glue and a self-adhesive mesh, for wound closure of medium-length surgical incisions has been reported. The aim of this study was to investigate the efficiency and cosmetic outcome of DP for wound closure in extra- and intradural pediatric neurological spine surgery. METHODS: In this prospective cohort study, 47 children underwent 50 spine procedures using DP for wound closure between 2018 and 2022 at a single institution. Patient demographic and surgical data were collected. The primary outcome was revision surgery for wound healing disorders, while secondary outcomes were infections, minor wound healing disorders, and both physician and parental satisfaction (parent-reported outcome measures [PROMs]) at last follow-up. RESULTS: Among 50 spinal (45 intra- and 5 extradural) interventions, 1 patient (2%) underwent revision surgery for a cutaneous CSF fistula and pseudomeningocele. Minor wound healing disorders occurred after 16 surgeries, which did not require surgical wound revision and resolved completely. No allergic reactions to DP or surgical site infections within 30 days were observed. The parents and the medical team described wound care as significantly facilitated since wound dressing changes were not needed. Three families (6.4%) encountered difficulties in wound care, and 46 (97.9%) were satisfied with DP. The cosmetic outcome based on PROMs was excellent, with a mean score of 8 (IQR 2) on a scale from 1 to 10. At long-term follow-up, a mean of 11.3 ± 10.7 months after surgery, physicians rated the cosmetic outcome on the visual analog scale (median score 9, IQR 1) and Hollander scale (median score 6, IQR 1). The outcomes were similar among the different pathologies and age groups and did not differ in patients with and without syndromic malformations. CONCLUSIONS: The application of DP is simple, enables good patient comfort, facilitates both professional and parental wound care, and leads to excellent cosmetic results. DP possibly aids in the reduction of postoperative CSF leakage and infections after pediatric neurological spine surgery.

High Performance Marine and Terrestrial Bioadhesives and the Biomedical Applications They Have Inspired.

This study has reviewed the naturally occurring bioadhesives produced in marine and freshwater aqueous environments and in the mucinous exudates of some terrestrial animals which have remarkable properties providing adhesion under difficult environmental conditions. These bioadhesives have inspired the development of medical bioadhesives with impressive properties that provide an effective alternative to suturing surgical wounds improving closure and healing of wounds in technically demanding tissues such as the heart, lung and soft tissues like the brain and intestinal mucosa. The Gecko has developed a dry-adhesive system of exceptional performance and has inspired the development of new generation re-usable tapes applicable to many medical procedures. The silk of spider webs has been equally inspiring to structural engineers and materials scientists and has revealed innovative properties which have led to new generation technologies in photonics, phononics and micro-electronics in the development of wearable biosensors. Man made products designed to emulate the performance of these natural bioadhesive molecules are improving wound closure and healing of problematic lesions such as diabetic foot ulcers which are notoriously painful and have also found application in many other areas in biomedicine. Armed with information on the mechanistic properties of these impressive biomolecules major advances are expected in biomedicine, micro-electronics, photonics, materials science, artificial intelligence and robotics technology.

2-Octyl cyanoacrylate, a hidden allergen, a common cause of postsurgical allergic contact dermatitis.

Background: 2-Octyl cyanoacrylate, a topical adhesive used for wound closure, is becoming a common cause for rashes in postsurgical patients. There is an increased number of cases of postsurgical contact dermatitis attributable to 2-octyl cyanoacrylate. Localized skin reactions to 2-octyl cyanoacrylate have been described in different case reports, but there are limited case reports of diffuse cutaneous allergic reactions. Objective: The aim of the study was to review our experience in patch testing with cyanoacrylates. Methods: We reported five cases of allergic contact dermatitis to 2-octyl cyanoacrylate, confirmed by a patch test. All the patients experienced a skin reaction a few days after surgery. The patients described an erythematous pruritic rash initially localized over the incision and that subsequently spread to surrounding areas. Two of the five patients developed a more widespread rash, which required a longer duration of systemic steroids. 2-Octyl cyanoacrylate remains an agent of low diagnostic suspicion as the possible cause of contact dermatitis after a surgical procedure. Results: All the patients, but one had a positive reaction to 2-octyl cyanoacrylate on PT. Four had a positive PT result, with one patient having a positive scratch test after a negative PT result. Testing on abraded skin further increased yield. Conclusion: Postsurgical patients should be evaluated by using a patch test if there is a clinical picture suggestive of contact dermatitis.

Comparing large-volume band ligators and cyanoacrylate injection for gastric variceal eradication: A prospective study.

BACKGROUND: The role of endoscopy in the ligation of gastric varices (GV) remains controversial. This study aimed to evaluate the efficacy of endoscopic band ligation (EBL) using large-volume ligators for the management of non-bleeding GV in patients with cirrhosis. METHODS: One hundred fifty-eight patients with non-bleeding GV due to cirrhosis were divided randomly into 2 groups: the EBL group and the endoscopic variceal obturation (EVO) group. The EBL group underwent EBL with large-volume ligators and the EVO group underwent tissue glue injection for the treatment of GV. Follow-up endoscopy was performed 3 to 4 weeks after endoscopic treatment. Patients were followed up for ≥6 months after treatment. Eradication, complication, and recurrence rates were evaluated and compared between groups. RESULTS: The type and size of GV were similar in both groups. No significant difference was found in the mean number of treatment sessions or eradication and recurrence rates after 6 months. Ulcer bleeding occurred in 2 EBL patients (2.50%) after ligation, whereas 8 EVO patients (10.25%) experienced bleeding due to glue extrusion. The bleeding rate after endoscopic treatment significantly differed between the groups. In the EVO group, 1 patient developed renal embolism after injection and 2 patients developed sepsis. The prevalence of postoperative fever was significantly higher in the EVO group than in the EBL group. CONCLUSION SUBSECTIONS: Large-volume band ligators have similar efficacy to tissue glue for eradicating GV, however, the former is safer. Nevertheless, multicenter studies are needed to further confirm these results.

Bio-macromolecular design roadmap towards tough bioadhesives.

Emerging sutureless wound-closure techniques have led to paradigm shifts in wound management. State-of-the-art biomaterials offer biocompatible and biodegradable platforms enabling high cohesion (toughness) and adhesion for rapid bleeding control as well as robust attachment of implantable devices. Tough bioadhesion stems from the synergistic contributions of cohesive and adhesive interactions. This Review provides a biomacromolecular design roadmap for the development of tough adhesive surgical sealants. We discuss a library of materials and methods to introduce toughness and adhesion to biomaterials. Intrinsically tough and elastic polymers are leveraged primarily by introducing strong but dynamic inter- and intramolecular interactions either through polymer chain design or using crosslink regulating additives. In addition, many efforts have been made to promote underwater adhesion via covalent/noncovalent bonds, or through micro/macro-interlock mechanisms at the tissue interfaces. The materials settings and functional additives for this purpose and the related characterization methods are reviewed. Measurements and reporting needs for fair comparisons of different materials and their properties are discussed. Finally, future directions and further research opportunities for developing tough bioadhesive surgical sealants are highlighted.

Alaska pollock gelatin sealant shows long-term efficacy and safety in a pulmonary air leakage rat model.

OBJECTIVES: Postoperative prolonged air leakage is a frequent complication following lung resection. We have shown the high adhesive quality of a newly developed sealant based on a hydrophobically modified Alaska pollock-derived gelatin (ApGltn) sealant in acute in vivo settings. The purpose of this study was to investigate the long-term efficacy and safety of ApGltn sealant using rats as a preclinical model. METHODS: An air leakage rat model with a 5-mm pleural defect was created, to which ApGltn sealant or fibrin sealant was applied. In both groups, the rats were evaluated on days 1, 7, 14 and 28. In the ApGltn sealant group, days 56 and 84 were added to evaluate absorption as sealant was still present on day 28. The number of rats in each subgroup was 4 (for a total of 40). Lung specimens and blood samples were obtained for histological and haematological assessment. RESULTS: No findings suggesting infection or air leakage were observed. ApGltn sealant was absorbed from day 56 to day 84. Histologically, although neutrophil and lymphocyte infiltrations on the lung side did not differ between groups, those on the sealant side were significantly less in the ApGltn sealant group. Blood sample tests revealed no significant findings suggesting inflammation or organ damage in either group. CONCLUSIONS: ApGltn sealant showed long-term sealing efficacy and safety with mild inflammation in a pulmonary air leakage rat model. ApGltn sealant is expected to be a safe and effective sealant for clinical applications.

Effectiveness of two extended-release buprenorphine formulations during postoperative period in neonatal rats.

Information on the effectiveness of a new long-lasting buprenorphine formulation, extended-release buprenorphine, in the neonatal rat is very limited. This study compares whether a high dose of extended-release buprenorphine (XR-Hi) attenuates thermal hypersensitivity for a longer period than a low dose of extended-release buprenorphine (XR-Lo) in a neonatal rat incisional pain model. Two experiments were performed. Experiment one: Male and female postnatal day-5 rat pups (n = 38) were randomly assigned to 1 of 4 treatment groups and received a subcutaneous administration of one of the following: 1) 0.9%NaCl (Saline), 0.1 mL; 2) sustained release buprenorphine (Bup-SR), 1 mg/kg; 3) XR-Lo, 0.65 mg/kg; and 4) XR-Hi, 1.3 mg/kg. Pups were anesthetized with sevoflurane in 100% O2 and a 5 mm long skin incision was made over the left lateral thigh and underlying muscle dissected. The skin was closed with surgical tissue glue. Thermal hypersensitivity testing (using a laser diode) and clinical observations were conducted 1 hour (h) prior to surgery and subsequently after 1, 4, 8, 24, 48, 72 h of treatment. Experiment two: The plasma buprenorphine concentration level was evaluated at 1, 4, 8, 24, 48, 72 h on five-day-old rat pups. Plasma buprenorphine concentration for all treatment groups remained above the clinically effective concentration of 1 ng/mL for at least 4 h in the Bup-SR group, 8 h in XR-Lo and 24 h in XR-Hi group with no abnormal clinical observations. This study demonstrates that XR-Hi did not attenuate postoperative thermal hypersensitivity for a longer period than XR-Lo in 5-day-old rats; XR-Hi attenuated postoperative thermal hypersensitivity for up to 4 h while Bup-SR and XR-Lo for at least 8 h in this model.

Investigation report on endoscopic management of esophagogastric variceal bleeding by Chinese endoscopists.

BACKGROUND: Esophagogastric variceal bleeding (EGVB) is a potentially life-threatening complication of portal hypertension. Endoscopic treatment combined with pharmacotherapy remains the mainstay in the management of acute variceal bleeding. AIM: This article intends to highlight the potential differences in the endoscopic management of EGVB in China. METHODS: A cross-sectional descriptive study was conducted. Endoscopists from 85 hospitals in 62 cities from 26 provinces were contacted by email. The items in questionnaire involved academic experience, screening, esophagogastric varices (EGV) classification, emergency treatment, and primary and secondary prophylaxis of EGVB by endoscopists with different lengths of experience. RESULTS: A total of 85 questionnaires were collected. There was no statistical difference in the selection of items (P < .05 indicated statistical significance). The majority of endoscopists (95.29%) offered EGV screening for patients with liver cirrhosis. The location, diameter, and risk factor classification was selected by 82.35% of endoscopists. Endoscopy + medication was preferred (42.35%) for the primary prophylaxis of moderate-to-severe EGVs. There was no statistical difference in emergency intervention time for active EGVB (P > .05). The response "patients receive emergency endoscopic intervention within 12 hours" was selected by 61.2% of the endoscopists. The preferred emergency treatment for EGVB was combination treatment (40%). Tissue adhesive embolization was selected for the treatment of gastric variceal bleeding by 74.12% of endoscopists; transjugular intrahepatic portosystemic stent shunt/percutaneous transhepatic variceal embolization were selected as remedial measures by 48.23% to 52.94% of endoscopists. In addition, 67.06% of endoscopists elected to perform secondary prophylaxis and treatment within 1 week after hemostasis. Endoscopy and endoscopy + medication were selected by 44.71% and 49.41% of endoscopists, respectively, for secondary prophylaxis. The choice of laboratory indicators did not differ with length of experience. CONCLUSIONS: There was no statistical difference in the endoscopic management of EGVB among Chinese endoscopists. The selection of diagnosis/treatment schemes was mainly based on guidelines and physician experience.

Enhanced burst strength of catechol groups-modified Alaska pollock-derived gelatin-based surgical adhesive.

Aortic anastomotic leak is a potentially fatal complication that can occur after treatment of aortic dissection or aneurysm. Several surgical adhesives have been used to prevent this complication, but all have problems with regard to tissue adhesion or biocompatibility. In the present study, we developed a surgical adhesive composed of boric acid-protected catechol groups-modified Alaska pollock-derived gelatin (Cat-ApGltn) and a poly(ethylene glycol)-based crosslinker (4S-PEG). By avoiding oxidation of catechol groups using boric acid, resulting Cat-ApGltn adhesive formed a strong hydrogel by double crosslinking: chemical crosslinking by 4S-PEG, and chemical and physical crosslinking by the catechol groups. The catechol groups modification contributed to increased bulk strength and decreased gelation time/swelling ratios. The Cat-ApGltn adhesive, in which 7.8 mol% of the amino groups of the original ApGltn (Org-ApGltn) were modified with catechol groups, demonstrated 2.3 times higher burst strength compared with the Org-ApGltn adhesive, and 3.9 times higher burst strength compared with a commercial fibrin adhesive. When the Cat-ApGltn adhesive was implanted subcutaneously into rats, it induced only weak inflammation similar to that induced by the Org-ApGltn adhesive, and was completely degraded within 2 months. Therefore, the Cat-ApGltn adhesive has great potential for use in the field of cardiovascular surgery.