Surgical Sealant Research Articles

Evaluation of an octyl group-modified Alaska pollock gelatin-based surgical sealant for prevention of postoperative adhesion

Postoperative adhesion can lead to an increase in the number of surgeries required, longer operation times, and high medical costs, resulting in the quality of life of the patient being lowered. To address these clinical problems, we developed a surgical sealant with anti-adhesion properties for the prevention of postoperative adhesion following application to the large intestine surface. The developed sealant was composed of octyl (C8) group-modified Alaska pollock-derived gelatin (C8-ApGltn) and a poly(ethylene)glycol-based 4-armed crosslinker (4S-PEG) (C8-ApGltn/4S-PEG sealant). Hydrophobic modification of the ApGltn molecule with C8 groups effectively enhanced both the burst strength on the large intestine surface and the bulk modulus. An in vitro anti-adhesion test indicated that cured C8-ApGltn/4S-PEG sealant adhered to the large intestine surface showed low adhesive strength compared with commercial anti-adhesion film. Besides, cured C8-ApGltn/4S-PEG sealant effectively inhibited albumin permeation and penetration of L929 fibroblasts. In vivo experiments using a rat peritoneal anti-adhesion model showed that C8-ApGltn/4S-PEG sealant acted as a sealing barrier on the target cecum surface and also provided an anti-adhesion barrier to prevent postoperative adhesion between the peritoneum and cecum. C8-ApGltn/4S-PEG sealant showed sufficient cytocompatibility and biodegradability and therefore has potential for use in gastroenterological surgery.

Treatment of Post-Ablation Bronchopleural Fistula Using Percutaneous Synthetic Hydrogel Surgical Sealant: Initial Experience of Safety and Efficacy

Purpose Bronchopleural fistula is a rare but serious complication of lung ablation, as it is difficult to treat and is associated with a high mortality rate. Standard therapy often relies on surgical pleurodesis, which can be particularly problematic in patients with poor baseline lung function. A minimally invasive treatment option for bronchopleural fistula may offer an alternative to surgery for appropriate patients. This case series describes the technique, safety and efficacy of percutaneously administered synthetic hydrogel surgical sealant in the treatment of post-ablation bronchopleural fistula in five patients. Materials and methods Retrospective chart review was carried out in five consecutive patients identified to have had BPF after lung ablation between 2009 and 2017 who were treated with percutaneous administration of synthetic hydrogel surgical sealant using CT guidance. Results The procedure was successfully carried out in all patients without immediate complications, and complete resolution of air leak was achieved in four of five patients (80%). Up to the most recent follow-up, no evidence of delayed complications or recurrent air leak was present (follow-up range 1 week-8 years). Conclusion The authors' initial experience shows that targeted surgical sealant is a potentially safe and effective alternative treatment of post-ablation persistent air leak.

Hydrogel-Tissue Adhesion Using Blood Coagulation Induced by Silica Nanoparticle Coatings.

The fixation of hydrogels to biological tissues is a major challenge conditioning the development of implants and surgical techniques. Here, coatings of procoagulant nanoparticles are devised which use the presence of blood to create adhesion between hydrogels and soft internal organs. Those nanostructured coatings are simply adsorbed at the hydrogel surfaces and can rapidly activate the formation of an interfacial blood clot acting as an adhesive joint. This concept is demonstrated on pig liver capsules with model poly(ethylene-glycol) membranes that are intrinsically poorly adhesive. In the absence of blood, ex vivo peeling tests show that coatings with aggregates of bare silica nanoparticles induce a 2- to 4-fold increase in adhesion energy as compared to the uncoated membrane (3 ± 2 J m-2). This effect is found to scale with the specific surface area of the coating. The highest adhesion energies produced by these nanoparticle-coated membranes (10 ± 5 J m-2) approach the value obtained with cyanoacrylate glue (33 ± 11 J m-2) for which tearing of the tissue is observed. Ex vivo pull-off tests show an adhesion strength of coated membranes around 5 ± 1 kPa, which is significantly reduced when operating in vivo (1.0 ± 0.5 kPa). Nevertheless, when blood is introduced at the interface, the in vivo adhesion strength can be improved remarkably with silica coatings, reaching 4 ± 2 kPa after 40 min contact. In addition, these silica-coated membranes can seal and stop the bleeding produced by liver biopsies very rapidly (<30 s). Such a combination of coagulation and particle bridging opens promising routes for better biointegrated hydrogel implants and improved surgical adhesives, hemostats, and sealants.

ENDOBRONCHIAL VALVES FOR THE MANAGEMENT BRONCHOPLEURAL FISTULA, EMPYEMA, AND TRAPPED LUNG

SESSION TITLE: Medical Student/Resident Procedures Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Bronchopleural fistula (BPF) is a rare complication of necrotizing pneumonia. It is associated with significant morbidity, mortality, and prolonged hospitalization1. Our case describes the bronchoscopic and pleural management approach of BPF that was complicated by empyema and trapped lung. CASE PRESENTATION: A 40-year-old woman who is diabetic and smoker was admitted to the intensive care unit for hypoxemic respiratory failure and septic shock. She was diagnosed with multifocal pneumonia secondary to methicillin-sensitive staphylococcus aureus. On day 2, a pigtail was placed for left tension pneumothorax. Despite successful extubation on day 8, a continuous air leak persisted. She remained febrile, septic with leukocytosis while on antibiotics. Chest CT scan revealed multifocal necrotizing pneumonia with left lung abscesses, left-sided empyema, left upper lobe (LUL) BPF, and right lung consolidations (Fig1). A posterior, left-sided 14F chest tube was placed, which drained frank pus. On day 19, the air leak was localized in the LUL and left lower lobe (LLL) anteromedial using balloon occlusion during Bronchoscopy. 8ml of CoSeal surgical sealant was administered to occlude the LUL segments and LLL anteromedial segment. The air leak completely resolved but recurred two days later. On repeat Bronchoscopy, 2 Zephyr endobronchial valves (EBV) were placed in the LUL bronchus and the LLL anteromedial segment which resolved the air-leak (Fig2). The left pleural space remained complicated with trapped lung, air-fluid level, and purulent drainage through the chest catheters. Two 20 French open chest tubes were placed to drain empyema, -40 cmH2O suction was applied to four chest tubes for two weeks to manage the trapped lung and prevent endobronchial spillage of the purulent secretions. Repeat CT chest showed improvement in left lung aeration and small residual hydropneumothorax. The chest tubes were removed on day 57, and she was discharged to acute rehabilitation. She was released home and remained asymptomatic at the three-month follow-up. DISCUSSION: The gold standard for the treatment is surgical management by video-assisted thoracoscopic surgery (VATS) or thoracotomy, but it can be challenging in the setting of active infection. Our case demonstrates the successful use of EBVs as a minimally invasive treatment option for persistent air leak that is complicated by empyema and trapped lung. EBVs allow retrograde passage of air and infected secretions while blocking anterograde airflow which permits the fistulous tract to heal. Applying high suction to all chest tubes was imperative in creating a sterile pleural space. The alternative management was an open-window thoracostomy and is usually associated with significant morbidity, mortality, and poor quality of life. CONCLUSIONS: The bronchoscopic management of BPF complicated by empyema and trapped lung may be successful in poor surgical candidates. Reference #1: 1] M. Lois, M. Noppen, Bronchopleural fistulas: an overview of the problem with special focus on endoscopic management, Chest 128 (2005) 3955–3965. DISCLOSURES: No relevant relationships by Kassem Harris, source=Web Response No relevant relationships by Anant Jain, source=Web Response no disclosure on file for Daniel Katzman; No relevant relationships by Anna Shengelia, source=Web Response

Management of Incidental Durotomy: Results from a Nationwide Survey Conducted by the French Society of Spine Surgery

To obtain real-life data on the most common practices used for management of incidental durotomy (ID) in France. Data were collected from spinal surgeons using a practice-based online questionnaire. The survey comprised 31 questions on the current management of ID in France. The primary outcome was the identification of areas of consensus and uncertainty on ID follow-up. A total of 217 surgeons (mainly orthopaedic surgeons and neurosurgeons) completed the questionnaire and were included in the analysis. There was a consensus on ID repair with 94.5% of the surgeons considering that an ID should always be repaired, if repairable, and 97.2% performing a repair if an ID occurred. The most popular techniques were simple suture or locked continuous suture (48.3% vs. 57.8% of surgeons). Nonrepairable IDs were more likely to be treated with surgical sealants than with an endogenous graft (84.9% vs. 75.5%). Almost two thirds of surgeons (71.6%) who adapted their standard postoperative protocol after an ID recommended bed rest in the supine position. Among these, 48.8% recommended 24 hours of bed rest, while 53.5% recommended 48 hours of bed rest. The surgeons considered that the main risk factors for ID were revision surgery (98.6%), patient's age (46.8%), surgeon's exhaustion (46.3%), and patient's weight (21.3%). This nationwide survey reflects the lack of a standardized management protocol for ID. Practices among surgeons remain very heterogeneous. Further consensus studies are required to develop a standard management protocol for ID.

Tissue Adhesive Properties of Functionalized Chitosan: A Comparative Study of Phenol, Catechol and Gallol

Tissue adhesives are greatly employed as surgical sealants for wound-healing patches and hemostatic dressing. However, achieving strong adhesion of wet tissues is still challenging because the bonding strength of biomedical adhesives is generally weakened by physiological fluids due to their high dielectric and ionic strengths. To overcome this challenge, bioinspired approaches have been adopted to enhance the wet adhesion of biocompatible polymers. Here, we synthesized a series of chitosan functionalized with bioinspired phenolic groups, i.e., phenol, catechol, and gallol, with similar modification rates. The bonding and sealing strengths of wet tissues by this functionalized chitosan were compared under similar conditions. We observed that the gallol group was the most effective in enhancing the tissue adhesion property of chitosan.

Mussel-inspired antimicrobial gelatin/chitosan tissue adhesive rapidly activated in situ by H2O2/ascorbic acid for infected wound closure

The development of minimally invasive surgery has created a demand for ideal medical adhesives exhibiting biocompatibility, biodegradability, antimicrobial activity, and strong adhesion to tissues in wet environments. However, as clinically approved surgical tissue glues suffer from poor adhesion activation, limited adhesion strength, and toxicity, novel tissue glues are highly sought after. Herein, a mussel-inspired injectable hydrogel was prepared from catechol- and methacrylate-modified chitosan/gelatin and shown to exhibit biocompatibility, inherent antimicrobial activity, and good adhesion to wet tissues. Moreover, as this gel could be applied onto tissue surfaces and cured in situ within seconds of body contact by a biocompatible and multifunctional redox initiator (H2O2-ascorbic acid), it was concluded to be a promising surgical sealant and wound dressing (even for infected wounds) accelerating wound healing.

Advances in Photoreactive Tissue Adhesives Derived from Natural Polymers

To stop blood loss and accelerate wound healing, conventional wound closure techniques such as sutures and staples are currently used in the clinic. These tissue-piercing wound closure techniques have several disadvantages such as the potential for causing inflammation, infections, and scar formation. Surgical sealants and tissue adhesives can address some of the disadvantages of current sutures and staples. An ideal tissue adhesive will demonstrate strong interfacial adhesion and cohesive strength to wet tissue surfaces. Most reported studies rely on the liquid-to-solid transition of organic molecules by taking advantage of polymerization and crosslinking reactions for improving the cohesive strength of the adhesives. Crosslinking reactions triggered using light are commonly used for increasing tissue adhesive strength since the reactions can be controlled spatially and temporally, providing the on-demand curing of the adhesives with minimum misplacements. In this review, we describe the recent advances in the field of naturally derived tissue adhesives and sealants in which the adhesive and cohesive strengths are modulated using photochemical reactions.

Production of a correctly assembled fibrinogen using transgenic silkworms.

Fibrinogen from human blood is used as a main component of coagulants, including surgical tissue sealants. The development of a recombinant human fibrinogen (rFib) is anticipated to eliminate the risks of blood-borne infections. Here, we report the efficient production of rFib in a transgenic silkworm system. A silkworm line carrying cDNAs of the fibrinogen Aα and γ chains (Aα/γ-silkworm) produced Aα and γ chains in its cocoons, however, the Bβ chains were not detected from cocoons of another silkworm line carrying the cDNA of fibrinogen Bβ chains (Bβ-silkworm). A silkworm line for all three fibrinogen chains was generated by crossing Aα/γ-silkworms with Bβ-silkworms, which secreted Aα2Bβ2γ2 fibrinogen (rFib) into cocoons at high contents. The N-terminal amino acid sequences of the three rFib chains were identical to those of the corresponding chains of native fibrinogen (nFib). The N-glycan profile of the rFib comprised oligomannose-type (53%), complex-type (34%), and paucimannose-type (13%); neither high-mannose-type (six or more mannose residues) nor core-fucosylated glycans were observed. The coagulation activity of the rFib was evaluated for the amount of thrombin-released fibrinopeptide A (FpA) and the kinetics for turbidity increase (non-covalent network formation) in the solution. FpA release rates were equivalent between rFib and nFib; by contrast, the kinetics of the turbidity increase for rFib were accelerated nearly two-fold, for both the rate and maximum value, compared to those of nFib. These results demonstrate that the rFib produced in the transgenic silkworm system is comparable to nFib in both physical and coagulative properties. This rFib is a promising candidate component for safe hemostatic pharmaceuticals.

Intra-Operative Amiodarone-Releasing Hydrogel to Prevent Post Lung Transplant Atrial Fibrillation: A Pilot Clinical Trial

The purpose of this study was to evaluate the effectiveness of topical amiodarone applied to the atria and pulmonary veins at the time of lung transplantation (LTx) in decreasing postoperative atrial fibrillation (POAF). Twenty patients undergoing LTx at a single institution were enrolled in this prospective pilot study and compared to 40 historical controls. An Amiodarone-containing hydrogel was created using CoSeal Surgical Sealant (Baxter Healthcare) and Amiodarone, which was applied to the pulmonary vein anastomoses and atria at time of LTx in the study group. The primary endpoint was development of POAF. Data for the control group was obtained by retrospective chart review. The demographic and clinical information for both groups is demonstrated in Table 1. In the study group, 6 patients (30%) developed POAF (Figure 1), 2 (10%) of which lasted less than 24 hours in duration. In the control group, 18 (52.9%) patients developed POAF, 9 (26.5%) of which lasted less than 24 hours in duration. Three patients in the study group and 4 control patients required cardioversion. In the study group, 20% of patients were discharged home on an anti-arrhythmic medication compared to 47.1% in the control group. There were no adverse outcomes related to the application of Amiodarone Hydrogel. In this small pilot study, the intra-operative application of Amiodarone-containing hydrogel to the pulmonary vein anastomoses and atria appeared to decrease the rates of POAF when compared to historical controls from the same institution.

Evaluation of a biocompatible sealant for on-demand repair of vascular defects—a chronic study in a large animal model

Existing surgical sealants fail to combine design requirements, such as sealing performance, on-demand activation and biocompatibility. The aim of this study was to compare the effectiveness and safety of the SETALIUM™ Vascular Sealant (SVS), a novel, on-demand activatable sealant, with the commercial sealant, BioGlue®, for the repair of vascular defects. In an in vivo porcine model, the use of SVS was compared with BioGlue, for sealing 2-mm defects of the carotid artery and jugular vein. Animals were followed for 7 days and 5 weeks (each time point and per experimental group, n = 4), respectively. The degree of stenosis and flow velocity was determined, and the local tissue response was evaluated. In vivo incision closure succeeded in all cases, and SVS was superior in clinical usability, enabled by its on-demand activation. Unlike BioGlue, SVS use did not induce stenosis and was associated with physiological blood flow in all cases. Moreover, closure with SVS was associated with a low inflammatory reaction and no thrombus formation or intima proliferation, in contrast to BioGlue. SVS demonstrated effective and rapid sealing of 2-mm vascular defects, with favourable biocompatibility compared to BioGlue. Thus, SVS seems to be an effective and safe vascular sealant.

Effect of temperature on gelation and cross-linking of gelatin methacryloyl for biomedical applications

Hydrogels with or without chemical cross-linking have been studied and used for biomedical applications, such as tissue repair, surgical sealants, and three dimensional biofabrication. These materials often undergo a physical sol–gel or gel–sol transition between room and body temperatures and can also be chemically cross-linked at these temperatures to give dimensional stability. However, few studies have clearly shown the effect of heating/cooling rates on such transitions. Moreover, only a little is known about the effect of cross-linking temperature or the state on the modulus after cross-linking. We have established rheological methods to study these effects, an approach to determine transition temperatures, and a method to prevent sample drying during measurements. All the rheological measurements were performed minimizing the normal stress build-up to compensate for the shrinking and expansion due to temperature and phase changes. We chemically modified gelatin to give gelatin methacryloyl and determined the degree of methacryloylation by proton nuclear magnetic resonance. Using the gelatin methacryloyl as an example, we have found that the gel state or lower temperature can give more rigid gelatin-based polymers by cross-linking under visible light than the sol state or higher temperature. These methods and results can guide researchers to perform appropriate studies on material design and map applications, such as the optimal operating temperature of hydrogels for biomedical applications. We have also found that gelation temperatures strongly depend on the cooling rate, while solation temperatures are independent of the heating rate.

An adhesive and injectable nanocomposite hydrogel of thiolated gelatin/gelatin methacrylate/Laponite® as a potential surgical sealant

Hemostatic adhesive hydrogels as sealants for surgical operations are one of the focus of the researches in the field of injectable materials. Herein, we evaluated the potential application of a mechanically robust nanocomposite hydrogel with significant adhesion strength and shorter blood clotting time. This hydrogel was composed of thiolated gelatin (Gel-SH) and gelatin methacrylate (GelMA) as the main matrix to support cell viability and proliferation, while polydopamine functionalized Laponite® (PD-LAP) were introduced to the structure to improve the mechanical properties, adhesion strength, and blood clotting. This hydrogel formed via Michael reaction between Gel-SH and GelMA, and covalent interaction between PD-LAP and hydrogel. Results revealed that presence of PD-LAP significantly controlled the swelling ratio, biodegradability, and mechanical properties of nanocomposite hydrogels. Tensile and compressive strength of nanocomposite hydrogels were measured in the range of 22–84 kPa and 54–153 kPa, respectively. Furthermore, nanocomposite hydrogels revealed excellent recovery ability, strong tissue adhesiveness and significantly less blood clotting time than Gel-SH/GelMA hydrogel (2.25 min). In the culture with L929 fibroblasts cells, viability more than 97% and high proliferation after 5 days of culture was estimated. The simplicity, low-cost, tunable mechanical properties, short blood clotting time, and cytocompatibility of the hydrogels composed of Gel-SH, GelMA, and PD-LAP highlight its potential as hemostat sealants.

A comprehensive review of topical hemostatic agents: The good, the bad, and the novel.

Uncontrolled exsanguination remains the leading cause of death for trauma patients, many of whom die in the pre-hospital setting. Without expedient intervention, trauma-associated hemorrhage induces a host of systemic responses and acute coagulopathy of trauma. For this reason, health care providers and prehospital personal face the challenge of swift and effective hemorrhage control. The utilization of adjuncts to facilitate hemostasis was first recorded in 1886. Commercially available products haves since expanded to include topical hemostats, surgical sealants, and adhesives. The ideal product balances efficacy, with safety practicality and cost-effectiveness. This review of hemostasis provides a guide for successful implementation and simultaneously highlights future opportunities.

Tissue Reaction to a Polyethylene Glycol-Based and Glutaraldehyde-Based Surgical Sealant in a Rabbit Aortic Anastomosis Model

Tissue Reaction to a Polyethylene Glycol-Based and Glutaraldehyde-Based Surgical Sealant in a Rabbit Aortic Anastomosis Model

An An Open-Label, Single Center, Retrospective Study to Evaluate Clinical Outcomes with Surgical Sealant in Bentall Procedures: A Cohort Study.

Cardiovascular surgery is associated with substantial risk for postoperative bleeding with increased patient morbidity and mortality. Numerous intraoperative techniques have been utilized to reduce this risk. This study was to assess postoperative bleeding-related parameters following Bentall procedures and to examine the impact of intraoperative surgical sealant application. The medical/surgical records of 100 consecutive Bentall procedure cases were examined retrospectively for perioperative surgical sealant use and postoperative bleeding-related outcomes. Of the 100 patient cases, three died during the postoperative period, and 97 were evaluable. Surgical sealant was utilized in 56 patient cases (57.8%). The utilization versus no utilization of surgical sealant was associated with significant reductions in most postoperative bleeding-related parameters, including less drainage (P = .028), resternotomy for hemorrhage (P = .036), transfusion of red blood cells (P = .022 at 48 hours; P = .027 total in-hospital), transfusion of fresh frozen plasma (P = .04 at 48 hours; P = .004 total in-hospital), and a higher percentage of cases not needing blood transfusion (P = .002). The surgical sealant group had longer cardiopulmonary bypass circuit (P = .016) and aortic cross-clamp time (P = .001), with no significant between-group differences in intubation time (P = .636) or intensive care unit duration (P = .294). When excluding urgent cases or Stanford type A aortic dissections, intensive care unit duration significantly was shorter in the surgical sealant group (P = .017). Surgical sealant use was not associated with any adverse events. The application of surgical sealant to the anastomosis suture line in Bentall procedures reduces postoperative drainage, bleeding, and transfusion utilization. Further studies are warranted to investigate these benefits in prospective, randomized clinical trials.

Feedback on the use of three surgical sealants for preventing prolonged air leak after robot-assisted anatomical lung resection.

Prolonged air leak (PAL) is the most common complication after lung resection. Several surgical sealants have been developed to reduce PAL, including fibrin-based (FS), polyethylene glycol-based (PEGS) and polyglycolic acid-based (PGAS) sealants. In this work we report our experience of surgical sealant use after robot-assisted lung resection. A 7-year retrospective study was conducted, including patients who had robot-assisted lobectomy or segmentectomy. Data were collected using a prospective national database. The use of surgical sealants was recorded in traceability sheets. PAL occurred in 60 of the 299 patients included. American Society of Anesthesiologists score (ASA) and index of prolonged air leak (IPAL) were higher for patients with sealants. In this group, operative time, chest drain duration and length of stay were significantly longer. PAL occurrence was significantly associated to sealant in univariate analysis (odds ratio =1.88, 95% CI: 1.07 to 3.36, P=0.03) but the association was slightly decreased when adjusting on IPAL and ASA score (Odds ratio =1.70, 95% CI: 0.94 to 3.10, P=0.08). Comparing sealants, more segmentectomies were performed in patients with PGAS (P=0.0013) and their operative time was shorter (P=0.0002). PAL occurrences were not different. Length of stay (P=0.0045) and operative time (P=0.0002) were longer in patients with PEGS who had more postoperative complications (P=0.024). This study did not identify a positive effect of surgical sealants for preventing PAL. However it highlighted the need to rationalize their use.

Improving the adhesion, flexibility, and hemostatic efficacy of a sprayable polymer blend surgical sealant by incorporating silica particles

Commercially available surgical sealants for internal use either lack sufficient adhesion or produce cytotoxicity. This work describes a surgical sealant based on a polymer blend of poly(lactic-co-glycolic acid) (PLGA) and poly(ethylene glycol) (PEG) that increases wet tissue adherence by incorporation of nano-to-microscale silica particles, without significantly affecting cell viability, biodegradation rate, or local inflammation. In functional studies, PLGA/PEG/silica composite sealants produce intestinal burst pressures that are comparable to cyanoacrylate glue (160 mmHg), ∼2 times greater than the non-composite sealant (59 mmHg), and ∼3 times greater than fibrin glue (49 mmHg). The addition of silica to PLGA/PEG is compatible with a sprayable in situ deposition method called solution blow spinning and decreases coagulation time in vitro and in vivo. These improvements are biocompatible and cause minimal additional inflammation, demonstrating the potential of a simple composite design to increase adhesion to wet tissue through physical, noncovalent mechanisms and enable use in procedures requiring simultaneous occlusion and hemostasis. Statement of SignificanceIncorporating silica particles increases the tissue adhesion of a polymer blend surgical sealant. The particles enable interfacial physical bonding with tissue and enhance the flexibility of the bulk of the sealant, without significantly affecting cytotoxicity, inflammation, or biodegradation. These studies also demonstrate how silica particles decrease blood coagulation time.This surgical sealant improves upon conventional devices because it can be easily deposited with accuracy directly onto the surgical site as a solid polymer fiber mat. The deposition method, solution blow spinning, allows for high loading in the composite fibers, which are sprayed from a polymer blend solution containing suspended silica particles. These findings could easily be translated to other implantable or wearable devices due to the versatility of silica particles.

Effectiveness of the sodium alginate as surgical sealant materials

Abstract Developing biocompatible tissue adhesives is a highly desired goal of the tissue engineering due to adverse effects of the sutures. Sodium alginate is a natural linear polysaccharide and has biocompatibility, non-toxicity, non-immunogenicity, biodegradability, antimicrobial activity, and can be simply gelled with divalent cations and used in a number of biomedical applications. So, in this study, we use simple Na-alginate solution as surgical sealant for wound close. We prepared 0.3% (w/w) alginate hydrogel solution and in vivo and in vitro experiment was carried out. Surgical incision along with bleeding was made on mouse dorsal surface and then closed the wound using either alginate solution or traditional suture materials. After 1 week and 2 weeks we found that alginate sample effectively sealed the bleeding wound and promote tissue regeneration without the aid of other surgical/dressing tools. We hypothesis that this suture-free wound closure may be very useful for those wounds on which sutures are hard to be placed and where aesthetic appearance are concerned. The convenient handling procedures, tissue adhesion, and aesthetic view of the wound surface, make alginate a promising materials for sealing applications of surgical practice.

Novel Alaska Pollock Gelatin Sealant Shows High Adhesive Quality and Conformability

Air leakage still remains a major problem in lung resection despite the introduction of surgical sealants. We have developed a novel sealant based on hydrophobically modified Alaska pollock-derived gelatin (ApGltn), which showed high adhesive quality invitro. In this study, we evaluated the adhesive quality and conformability of our ApGltn sealant compared with a fibrin sealant. The adhesive quality of the sealants was evaluated using excised porcine lungs with ventilation. Pleural defects were created, to which the ApGltn sealant or fibrin sealant was applied. Pressure resistance was assessed using a stepwise increase of airway pressure. Conformability was evaluated by measuring the area of the sealant for its maximum conformity on the gradually inflated lung surface. Leak and burst pressures of the ApGltn sealant were significantly higher than those of the fibrin sealant (47.1 ± 10.5 cm H2O and 52.3 ± 9.4 cm H2O versus 33.9 ± 6.0 cm H2O and 37.5 ± 5.9 cm H2O, respectively). Maximum expansion areas of the ApGltn sealant and fibrin sealant were 2652.4 ± 324.6 mm2 and 1276.6 ± 323.5 mm2, respectively. The ApGltn sealant also showed higher adhesive quality and conformability compared with the fibrin sealant. Histological examination confirmed that the ApGltn sealant showed tight adhesion to the pleural surface, while a gap was observed with the fibrin sealant. The ApGltn sealant showed higher adhesive quality and conformability than the fibrin sealant in an excised porcine lung model. We expect that, in the future, the ApGltn sealant will be used for lung resections in clinical settings.