Cytotoxicity of Cyanoacrylate-Based Tissue Adhesives and Short-Term Preclinical In Vivo Biocompatibility in Abdominal Hernia Repair

[Evaluation of the Cytotoxicity of Commercially Available Nail Adhesives]

Nail tips are nail art materials that can be attached to the nail with adhesives. Recently, nail/finger injuries related to nail tips have been reported and one of the causes is considered to be the adhesives used for attaching nail tips. The components of nail adhesives are mostly cyanoacrylate, which is also used as an industrial instant adhesive. During curing, cyanoacrylate adhesives release formaldehyde through hydrolysis. When it is marketed as a nail adhesive, there is no regulation regarding its formaldehyde amount nor obligation to indicate its ingredients in Japan. Additionally, a biological safety test is not required for nail adhesives. Thus, because the safety of nail adhesives is inadequately confirmed, it is necessary to investigate their biological safety. Therefore, we purchased 5 commercially available nail adhesives and 1 medical adhesive and examined their formaldehyde content and cytotoxicity. We examined the cytotoxicity of the adhesives in V79 cells by a colony forming assay. In this test, 5 nail adhesives showed higher toxicity than 1 medical adhesive. Formaldehyde concentrations in the extract of adhesives were as follows: 17.5 to 24.2 μg/mL for nail adhesives and 7.4 μg/mL for medical adhesives. Cyanoacetate did not elicit cytotoxicity at the final concentration up to 1000 μM. However, formaldehyde showed cytotoxicity, with an IC₅₀ of 79 μM (2.4 μg/mL). Taken together, the cytotoxicity of nail adhesives could be due to the formaldehyde generated by the hydrolysis of cyanoacrylate. It seems important that nail adhesives will be regulated by obligation and enhanced safety in the future.

Pre-clinical assay of the tissue integration and mechanical adhesion of several types of cyanoacrylate adhesives in the fixation of lightweight polypropylene meshes for abdominal hernia repair

INTRODUCTION

Lightweight (LW) polypropylene (PP) meshes better adapt to host tissue, causing less fibrosis and inflammatory responses than high-density meshes. Mesh fixation using tissue adhesives (TA) that replace conventional sutures may improve the process of hernia repair and tissue trauma. This preclinical study compares the behavior of different cyanoacrylate-based adhesives in the fixation of LW-PP meshes for hernia repair.

METHODS

Partial abdominal wall defects were repaired using LW-PP Optilene meshes in New Zealand rabbits. The following groups were established according to the mesh fixation method: Suture (control), Glubran 2 (n-butyl), Ifabond (n-hexyl), SafetySeal (n-butyl) and Evobond (n-octyl). At 14, 90 and 180 days after surgery, the recovered implants were examined to assess the host tissue integration, the macrophage response and the biomechanical strength.

RESULTS

All the groups showed optimal host tissue incorporation regardless of the fixation procedure. Significantly increased levels of collagen 1 and collagen 3 gene expression (p<0.001) were observed at 14 days compared to the medium- and long-term durations, where the Suture and Glubran groups showed the highest expression of collagen 1. All the adhesives increased the macrophage reaction (p<0.001) compared to sutures at all implant times. Maximal macrophage response was observed in the short-term Glubran group (p<0.01) compared to the rest of the groups. Although SafetySeal and Evobond did not reach the biomechanical resistance of sutures at 14 days, all the adhesives did reach this level in the medium- to long-term periods, providing significantly higher resistance (p<0.05).

CONCLUSIONS

All the cyanoacrylates, despite inducing a significantly increased macrophage response versus sutures, showed optimal host tissue integration and long-term mechanical behavior; thus, they might be good choices for LW-PP mesh hernia repairs.

Surface modification of polypropylene surgical meshes for improving adhesion with poloxamine hydrogel adhesive

Tissue adhesive has notable clinical benefits in hernia repair fixation. A novel poloxamine tissue adhesive was previously shown to successfully bond collagen tissue with adequate adhesive strength. In application related to attachment of polypropylene (PP) mesh, the adhesive strength between the mesh and poloxamine hydrogel adhesive is limited by the hydrophobicity of PP monofilaments and lack of covalent bond formation. The purpose of this study was to compare two different surface modifications [bovine serum albumin (BSA) adsorption and poly-glycidyl methacrylate/human serum albumin (PGMA/HSA) grafting] of PP mesh for improving the adhesive strength between poloxamine hydrogel adhesive and PP mesh. The PGMA/HSA surface modification significantly improved the adhesive strength for meshes attached with poloxamine hydrogel tissue adhesive compared with unmodified meshes and meshes modified by BSA adsorption. An area of 1 cm² adhesive provided for a maximum adhesive strength of 65-70 kPa for meshes modified by PGMA/HSA, 4-13 kPa for meshes modified by BSA, and 22-45 kPa for unmodified meshes. Optical microscopy and infrared spectroscopy (FTIR) confirmed the improved adhesive strength was achieved through mechanical interlock of the hydrogel tissue adhesive into the PP mesh pores and chemical bonding of the albumin after successful PGMA/HSA grafting onto the PP monofilaments. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1047-1055, 2019.

Electric- Field-Modified In Situ Precise Deposition of Electrospun Medical Glue Fibers on the Liver for Rapid Hemostasis

Precise deposition of nanofibers is still an important issue in the applications of electrospinning (e-spinning), especially in rapid hemostasis of organs such as the liver, lung, and kidney. In this study, we propose an electric field-modified e-spinning technique with a metal cone attached to the spinning nozzle to realize controllable precise deposition of fibers. The deposition range of the e-spun fibers is tunable by changing the size of the metal cone, and the mechanism is attributed the focused electric field verified by theoretical simulations. This electric field-modified e-spinning method was further used to in situ precisely deposit medical glue N-octyl-2-cyanoacrylate (NOCA) fibers onto the resection site of rat liver to realize rapid hemostasis within 10 s. Postoperative pathological results indicate that less inflammatory response and tissue adhesion are observed in this electric field-modified e-spinning group compared with that of traditional airflow-assisted group. This technique combined with our designed handheld e-spinning device could be used in emergency medical treatment, clinics, field survival, and home care for its portability and precise deposition characteristics.

Towards an arthritis flare-responsive drug delivery system

Local delivery of therapeutics for the treatment of inflammatory arthritis (IA) is limited by short intra-articular half-lives. Since IA severity often fluctuates over time, a local drug delivery method that titrates drug release to arthritis activity would represent an attractive paradigm in IA therapy. Here we report the development of a hydrogel platform that exhibits disassembly and drug release controlled by the concentration of enzymes expressed during arthritis flares. In vitro, hydrogel loaded with triamcinolone acetonide (TA) releases drug on-demand upon exposure to enzymes or synovial fluid from patients with rheumatoid arthritis. In arthritic mice, hydrogel loaded with a fluorescent dye demonstrates flare-dependent disassembly measured as loss of fluorescence. Moreover, a single dose of TA-loaded hydrogel but not the equivalent dose of locally injected free TA reduces arthritis activity in the injected paw. Together, our data suggest flare-responsive hydrogel as a promising next-generation drug delivery approach for the treatment of IA.

Artificial controlled model of blood circulation system for adhesive evaluation

Since there are several casualties due to uncontrolled bleeding resulting from simple injury to surgery, effective styptic or vessel adhesives are important; however, their development is limited by the lack of standardized systems to evaluate potential compounds. The current study outlines the development of an aorta styptic evaluation system, comprising of decellularized swine aorta tissue and a heart pump-mimicking system. Although the cells in the swine aorta were removed, the structural stability of the aorta was sustained due to the maintenance of the extracellular matrix. Using a control adhesive, Cyanoacrylate, the developed model was found to have similar adhesive efficacy to intact aorta. The circulatory-mimicking system was designed to mimic the beat rate and strength of blood-flow from the heart, which was necessary to evaluate the adherent efficacy. The decellularized aorta improves instabilities of intact tissues, which occurs on account of storage and origin, thereby allowing for a more standardized system. The system was able to simulate several symptoms of circulation, according to patient age and health, by adjusting pumping frequency and intensity. Therefore, this system can be used as a standardized evaluation system for screening adhesives. Further, it would also evaluate other medical devices, such as stent or medications.

Seroma following transabdominal preperitoneal patch plasty (TAPP): incidence, risk factors, and preventive measures

Background

The reported range of seroma formation in the literature after TEP repair is between 0.5 and 12.2% and for TAPP between 3.0 and 8.0%. Significant clinical factors associated with seroma formation include old age, a large hernia defect, an extension of the hernia sac into the scrotum, as well as the presence of a residual indirect sac. Seroma formation is a frequent complication of laparoendoscopic mesh repair of moderate to large-size direct (medial) inguinal hernia defects. This present analysis of data from the Herniamed Hernia Registry now explores the influencing factors for seroma formation in male patients after TAPP repair of primary unilateral inguinal hernia.

Methods

In total, 20,004 male patients with TAPP repair of primary unilateral inguinal hernia were included in uni- and multivariable analysis.

Results

Univariable analysis revealed the highly significant impact of the fixation technique on the seroma rate (non-fixation 0.7% vs. tacks 2.1% vs. glue 3.9%; p < 0.001). Multivariable analysis showed that glue compared to tacks (OR 2.077 [1.650; 2.613]; p < 0.001) and non-fixation (OR 5.448 [4.056; 7.317]; p < 0.001) led to an increased seroma rate. A large hernia defect (III vs. I: OR 2.868 [1.815; 4.531]; p < 0.001; II vs. I: OR 2.157 [1.410; 3.300]; p < 0.001) presented a significantly higher risk of seroma formation. Likewise, medial compared to lateral inguinal hernias had a higher seroma rate (OR 1.272 [1.020; 1.585]; p = 0.032).

Conclusions

Mesh fixation with tacks or glue, a larger hernia defect, and medial defect localization present a higher risk for seroma development in TAPP inguinal hernia repair.

Therapeutic ureteral occlusion with Ifabond cyanoacrylate glue: an interesting solution

OBJECTIVE

The aim of this study was to present a novel approach for complete and permanent ureteral occlusion using a percutaneous injection of Ifabond cyanoacrylate glue.

METHODS

We describe in detail all the steps of our surgery, performed on a 79-year-old patient with urinary leakage from ureteral stump following radical cystectomy. N-hexyl-cyanoacrylate glue (Ifabond) was used to occlude the distal ureter and solve the leakage.

RESULTS

Our approach was successful, sparing our already frail patient further surgical procedures. Six months pyelography confirmed the complete ureteral blockage with absence of extravasation.

CONCLUSIONS

In complicated scenarios with urinary leakages and frail patients, synthetic glues such as Ifabond might represent an interesting therapeutic option to solve the fistulas, leading to durable success with a minimally invasive approach.

Sutures versus new cyanoacrylates in prosthetic abdominal wall repair: a preclinical long-term study

BACKGROUND

As an alternative to sutures, meshes used for hernia repair can be fixed using cyanoacrylate-based adhesives. Attempts to improve these adhesives include alkyl-chain lengthening to reduce their toxicity. This preclinical study compares the long-term behavior of cyanoacrylates of different chain lengths already used in hernia repair and new ones for this application.

MATERIALS AND METHODS

Partial abdominal wall defects were repaired using a Surgipro mesh in 18 New Zealand White rabbits, and groups were established according to the mesh fixation method: sutures (control), Glubran 2 (n-butyl), Ifabond (n-hexyl), and the new adhesives SafetySeal (n-butyl), and Evobond (n-octyl). Six months after surgery, recovered implants were examined to assess adhesive degradation, host tissue reaction, and biomechanical strength.

RESULTS

All the cyanoacrylate groups showed good host tissue incorporation in the meshes. Macrophage responses to Glubran and Ifabond were quantitatively greater compared with sutures. Cell damage caused by the adhesives was similar, and only Glubran induced significantly more damage than sutures. Significantly lower collagen 1/3 messenger RNA expression was induced by Ifabond than the remaining fixation materials. No differences were observed in collagen expression except slightly reduced collagen I deposition in Glubran/Ifabond and collagen III deposition in the suture group. Mechanical strengths failed to vary between the suture and cyanoacrylate groups.

CONCLUSIONS

All cyanoacrylates showed good long-term behavior and tolerance irrespective of their long or intermediate chain length. Cyanoacrylate residues persisted at 6 mo, indicating their incomplete degradation. Biomechanical strengths were similar both for the adhesives and sutures.

Pregnancy after Orthotopic Ovarian Tissue Transplantation Using N-hexyl-2-cyanoacrylate

Cryopreservation of ovarian tissue in advance of cytotoxic therapies and later transplantation of the tissue is being performed increasingly often, and the total success rates in terms of pregnancy and delivery have been described in case series. Most pregnancies were achieved after orthotopic transplantation of tissue (in the peritoneum or the remaining ovary); however, treatment of the transplantation site during surgery is controversial. In this observational case-series study, we include four patients who underwent ovarian tissue transplantation between 2012 and 2016 by laparoscopy. Previously ovarian tissue was cryopreserved with slow freezing protocol prior to chemo- and/or radiotherapy. After cancer remission, the cryopreserved ovarian tissues were orthotopically re-transplanted in the ovarian medulla by laparoscopy, using N-hexyl-2-cyanoacrylate as an absorbable adhesion barrier. All patients regained ovarian function between 8 and 24 weeks after transplantation, as shown by follicle development and estrogen production. In patients 1 and 2 the ovarian function ended one year after transplantation. Patient 3 has regular menstrual cycles 2 years after the transplant and patient 4 currently has an ongoing spontaneous pregnancy.

The use of N-hexyl-2 cyanoacrylate can facilitate the placement of ovarian pieces in orthotopic transplantation by laparoscopy without affecting the restoration and duration of ovarian activity.

Effect of 2-octylcyanoacrylate on placenta derived mesenchymal stromal cells on extracellular matrix

PURPOSE

Determine the effect of 2-octylcyanoacrylate on placenta derived mesenchymal stromal cells (PMSCs) seeded onto extracellular matrix (ECM) in order to assess its biocompatibility as a potential adhesive for in-vivo fetal cell delivery.

METHODS

PMSCs isolated from chorionic villus tissue were seeded onto ECM. A MTS proliferation assay assessed cellular metabolic activity at various time points in PMSC-ECM with direct, indirect, and no glue contact. Conditioned media collected prior to and 24 hours after glue exposure was analyzed for secretion of human brain-derived neurotrophic factor, hepatocyte growth factor, and vascular endothelial growth factor.

RESULTS

Direct and indirect contact with 2-octylcyanoacrylate results in progressively decreased cellular metabolic activity over 24 hours compared to no glue controls. Cells with direct contact are less metabolically active than cells with indirect contact. 24 hours of glue exposure resulted in suppression of growth factor secretion that is near complete with direct contact.

DISCUSSION

Exposure to 2-octylcyanoacrylate results in decreased metabolic activity and decreased measurable secretion of growth factors by PMSCs seeded onto ECM. Thus, the application of 2-octylcyanoacrylate glue should be limited when working with cell-engineered scaffolds as its inhibitory effects on cell growth and secretory function can limit the therapeutic potential of cell-based interventions.

Cyanoacrylic tissue glues: Biochemical properties and their usage in urology

Tissue adhesives are being used in medical and cosmetic industries and first aid for a long time. But their everyday usage has not been widespread. Only case report information is available about their usage. Despite good and meaningful results after they were used, there is lack of standard information that gives idea of about in which cases they could be helpful. Nowadays, cyanoacrylates are used in the surgery more frequently. In this review, we wanted to oversee the biochemical properties and the urological utilisation areas of cyanoacrylates.