Cabazitaxel-loaded poly(alkyl cyanoacrylate) nanoparticles: toxicity and changes in the proteome of breast, colon and prostate cancer cells.

Nanoparticles composed of poly(alkyl cyanoacrylate) (PACA) have shown great promise due to their biodegradability and high drug loading capacity. Development of optimal PACA nanocarriers requires detailed analysis of the overall cellular impact exerted by PACA variants. We here perform a comprehensive comparison of cabazitaxel (CBZ)-loaded nanocarriers composed of three different PACA monomers, i.e. poly(n-butyl cyanoacrylate) (PBCA), poly(2-ethylbutyl cyanoacrylate) (PEBCA) and poly(octyl cyanoacrylate) (POCA). The cytotoxicity of drug-loaded and empty PACA nanoparticles were compared to that of free CBZ across a panel of nine cancer cell lines by assessing cellular metabolism, proliferation and protein synthesis. The analyses revealed that the cytotoxicity of all CBZ-loaded PACAs was similar to that of free CBZ for all cell lines tested, whereas the empty PACAs exerted much lower toxicity. To increase our understanding of the toxic effects of these treatments comprehensive MS-based proteomics were performed with HCT116, MDA-MB-231 and PC3 cells incubated with PACA-CBZ variants or free CBZ. Interestingly, PACA-CBZ specifically led to decreased levels of proteins involved in focal adhesion and stress fibers in all cell lines. Since we recently demonstrated that encapsulation of CBZ within PEBCA nanoparticles significantly improved the therapeutic effect of CBZ on a patient derived xenograft model in mice, we investigated the effects of this PACA variant more closely by immunoblotting. Interestingly, we detected several changes in the protein expression and degree of phosphorylation of SRC-pathway proteins that can be relevant for the therapeutic effects of these substances.

Rare chemical burns: Review of the Literature.

There are many chemicals that can cause burns. Although they are generally acidic and basic in nature, there are more than one million known chemical compounds, of which 300 have been declared highly hazardous chemical substances by the National Fire Protection Society. Chemical burns account for approximately 10.7% of all burn injuries and 30% of deaths because of burns. Chemicals can be classified as acid, alkali, organic, and inorganic compounds. Acids act by denaturing and coagulating proteins. Alkaline burns cause deeper burns than acid burns.

[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.

Cytotoxicity of Poly(Alkyl Cyanoacrylate) Nanoparticles.

Although nanotoxicology has become a large research field, assessment of cytotoxicity is often reduced to analysis of one cell line only. Cytotoxicity of nanoparticles is complex and should, preferentially, be evaluated in several cell lines with different methods and on multiple nanoparticle batches. Here we report the toxicity of poly(alkyl cyanoacrylate) nanoparticles in 12 different cell lines after synthesizing and analyzing 19 different nanoparticle batches and report that large variations were obtained when using different cell lines or various toxicity assays. Surprisingly, we found that nanoparticles with intermediate degradation rates were less toxic than particles that were degraded faster or more slowly in a cell-free system. The toxicity did not vary significantly with either the three different combinations of polyethylene glycol surfactants or with particle size (range 100-200 nm). No acute pro- or anti-inflammatory activity on cells in whole blood was observed.

Adhesivos de cianoacrilato en cirugía oral y maxilofacial / Cyanoacrylate adhesives in oral and maxillofacial surgery

RESUMEN: Los adhesivos de cianoacrilatos (ACA) son materiales sintéticos con propiedades adhesivas. Al ser aplicados en los tejidos polimerizan uniéndose con el tejido subyacente. Desde la década de los 70' se han explorado sus aplicaciones quirúrgicas para el cierre de heridas y fístulas, control de sangrado y fijación de injertos, entre otros, siendo su uso como alternativa para el cierre de heridas en piel y mucosas uno de los más estudiados. Los ACA presentan un limitado grado de absorción, sin evidencia de efectos tóxicos sistémicos. Tienen la ventaja de ser aplicados de forma rápida, indolora, con efecto antibacteriano y hemostático según los reportes de la literatura, pero presentan una reducida fuerza de tensión. El objetivo de esta revisión de la literatura es describir los usos y aplicaciones de los ACA, con enfoque en la cirugía oral y maxilofacial, evaluando de forma crítica sus aplicaciones.

ABSTRACT: The cyanoacrylate adhesives (ACA) are synthetic materials with adhesive properties. When is applied in tissues, it polymerizes and bonds with the underlying tissue. Since the 70s' have been explored their surgical applications for closing wounds, fistulas, bleeding control, and graft fixation, among others. Its use as an alternative for closing wounds in skin and mucous is one of the most studied. The ACA have a limited absorption degree, with no evidence of systemic toxic effects. They have the advantage of being applied quickly, painlessly, with antibacterial effect and hemostatic according to the report of literature, but with reduced tensile strength. The objective of this literature review is to describe the use and applications of ACA, with focus on oral and maxillofacial surgery, with a critically evaluation of their applications.

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.

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

BACKGROUND: Cyanoacrylate(CA)-based tissue adhesives, although not widely used, are a feasible option to fix a mesh during abdominal hernia repair, due to its fast action and great bond strength. Their main disadvantage, toxicity, can be mitigated by increasing the length of their alkyl chain. The objective was to assess the in vitro cytotoxicity and in vivo biocompatibility in hernia repair of CAs currently used in clinical practice (Glubran(n-butyl) and Ifabond(n-hexyl)) and a longer-chain CA (OCA(n-octyl)), that has never been used in the medical field. METHODS: Formaldehyde release and cytotoxicity of unpolymerized(UCAs) and polymerized CAs(PCAs) were evaluated by macroscopic visual assessment, flow cytometry and Alamar Blue assays. In the preclinical evaluation, partial defects were created in the rabbit abdominal wall and repaired by fixing polypropylene prostheses using the CAs. At 14 days post-surgery, animals were euthanized for morphology, macrophage response and cell damage analyses. RESULTS: Formaldehyde release was lower as the molecular weight of the monomer increased. The longest side-chain CA(OCA) showed the highest cytotoxicity in the UCA condition. However, after polymerization, was the one that showed better behavior on most occasions. In vivo, all CAs promoted optimal mesh fixation without displacements or detachments. Seroma was evident with the use of Glubran, (four of six animals: 4/6) and Ifabond (2/6), but it was reduced with the use of OCA (1/6). Significantly greater macrophage responses were observed in groups where Glubran and Ifabond were used vs. sutures and OCA. TUNEL-positive cells were significantly higher in the Glubran and OCA groups vs. the suture group. CONCLUSIONS: Although mild formaldehyde release occurred, OCA was the most cytotoxic during polymerization but the least once cured. The CAs promoted proper mesh fixation and have potential to replace traditional suturing techniques in hernia repair; the CAs exhibited good tissue integration and effective short-term biocompatibility, with the slightest seroma and macrophage response induced by OCA.

Comparison of 2-Ethyl-Cyanoacrylate and 2-Butyl-Cyanoacrylate for Use on the Calvaria of CD1 Mice.

Short-chain cyanoacrylates (SCCA), such as ethyl-2-cyanoacrylate (KrazyGlue, Aron Alpha, Columbus, OH) are commonly used as commercial fast-acting glues. Although once used in clinical medicine as skin adhesives, these products caused tissue toxicity and thus their use in live tissue was discontinued. SCCA were replaced by longer-chain versions (LCCA), such as butyl-cyanoacrylate (Vetbond, 3M, St Paul, Minnesota), which were found to be less toxic than the short-chain formulations. Some researchers prefer to use SCCA due to the belief that they create a stronger bond than do the longer-chain counterparts. In survival surgeries, we compared the bone thickness, bone necrosis, fibrosis, inflammation, and bone regeneration in the calvaria of control (naïve), surgery-only, SCCA-treated, and LCCA-treated mice (n = 20 per group). At 1 and 14 d after surgery, all mice except those treated with SCCA showed statistically similar bone measurements to those of the naive control group. The SCCA group had significantly less bone regeneration than did all other groups. These results suggest that the application of SCCA causes bone damage resulting in the loss of bone regeneration. This finding may assist investigators in choosing a tissue glue for their studies and may support the IACUC in advocating the use of pharmaceutical-grade tissue glues.

N-butyl cyanoacrylate- and alpha-cyanoacrylate induced hepatotoxicity and venous sclerosis in a rabbit model.

BACKGROUND AND STUDY AIMS: Tissue adhesives are commonly used. The aim of this study was to assess the efficacy and hepatotoxicity of intravenous injection of N-butyl cyanoacrylate versus alpha-cyanoacrylate in a rabbit model. MATERIALS AND METHODS: A total of 20 rabbits were divided into three groups: group I included four rabbits injected with lipiodol in the dorsal vein of a pinna (control group); group II included eight rabbits injected with N-butyl cyanoacrylate/lipiodol; and group III included eight rabbits injected with alpha-cyanoacrylate/lipiodol. All animals were left under normal living conditions for 1week, and then euthanised. Specimens of ear and liver were taken and fixed in 10% formalin saline for histological examination. Secondary fixation was performed using Bouin solution. Specimens of ear were decalcified in ethylenediaminetetraacetic acid (EDTA) at room temperature for 3months. Then, all specimens were processed, embedded in paraffin, sectioned, and stained with haematoxylin and eosin stains for microscopic examination. RESULTS: Microscopic examination of all specimens of the control group revealed normal structure of pinna and liver tissue. Both test groups demonstrated a wide variability of structural changes ranging from oedema and congestion to necrosis and marked cellular inflammatory infiltration. The two groups were compared using a self-designed inflammatory score. This revealed that alpha-cyanoacrylate caused more venous sclerosis with extensive perivenous reaction and hepatotoxicity than both N-butyl cyanoacrylate and control (p<0.05 and p<0.05). N-butyl cyanoacrylate was also found to cause more venous sclerosis and hepatotoxicity than control (p<0.05). CONCLUSION: This study suggested that injection of Krazy Glue, either the clinically usable N-butyl cyanoacrylate or the commercially available alpha-cyanoacrylate, caused comparable venous sclerosis. Unfortunately, both induced significant hepatotoxicity. Therefore, neither of them should be used unless all other safe options are absent. Larger studies have to be conducted and effects of these components on other organs should be investigated; however, caution must be exercised in their clinical use.

Enhanced biocompatibility and wound healing properties of biodegradable polymer-modified allyl 2-cyanoacrylate tissue adhesive.

As poly L-lactic acid (PLLA) is a polymer with good biocompatibility and biodegradability, we created a new tissue adhesive (TA), pre-polymerized allyl 2-cyanoacrylate (PACA) mixed with PLLA in an effort to improve biocompatibility and mechanical properties in healing dermal wound tissue. We determined optimal mixing ratios of PACA and PLLA based on their bond strengths and chemical structures analyzed by the thermal gravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopy. In vitro biocompatibility of the PACA/PLLA was evaluated using direct- and indirect-contact methods according to the ISO-10993 cytotoxicity test for medical devices. The PACA/PLLA have similar or even better biocompatibility than those of commercially available cyanoacrylate (CA)-based TAs such as Dermabond® and Histoacryl®. The PACA/PLLA were not different from those exposed to Dermabond® and Histoacryl® in Raman spectra when biochemical changes of protein and DNA/RNA underlying during cell death were compared utilizing Raman spectroscopy. Histological analysis revealed that incised dermal tissues of rats treated with PACA/PLLA showed less inflammatory signs and enhanced collagen formation compared to those treated with Dermabond® or Histoacryl®. Of note, tissues treated with PACA/PLLA were stronger in the tensile strength compared to those treated with the commercially available TAs. Therefore, taking all the results into consideration, the PACA/PLLA we created might be a clinically useful TA for treating dermal wounds.

Drug-free chitosan coated poly(isobutylcyanoacrylate) nanoparticles are active against trichomonas vaginalis and non-toxic towards pig vaginal mucosa.

PURPOSE: The present work reports a non-conventional therapeutic strategy based on the use of vaginally-applied formulations for the treatment of trichomoniasis due to Trichomonas vaginalis without adding a drug. METHODS: The formulations were based on a thermosensitive pluronic® F127 hydrogel containing mucoadhesive poly(isobutylcyanoacrylate) nanoparticles coated with a mixture of chitosan and thiolated chitosan (75/25 wt%). The nanoparticles were obtained by anionic emulsion polymerization of isobutylcyanoacrylate. The anti-T. vaginalis activity of the formulations was evaluated in vitro. RESULTS: Chitosan-coated nanoparticles showed a strong anti-T. vaginalis activity at 100 µg/mL independently on the proportion of thiolated chitosan. No anti-T. vaginalis activity was reported neither with chitosan-uncoated poly(isobutylcyanoacrylate) nanoparticles nor with chitosan used as a solution. These results suggest that the anti-T. vaginalis activity was related to poly(isobutylcyanoacrylate) nanoparticles but only when they are coated with chitosan. Histological analysis of ex vivo pig vaginal mucosa in contact with pluronic® F127 hydrogel containing poly(isobutylcyanoacrylate) nanoparticles coated with the mixture chitosan/thiolated chitosan (75/25 wt%) did not reveal any toxicity. CONCLUSION: This study demonstrated that poly(isobutylcyanoacrylate) nanoparticles coated with chitosan were active against T. vaginalis without adding a drug. Besides their anti-T. vaginalis activity, the formulations are non-toxic towards pig vaginal mucosa.

Mechanical and cytotoxicity testing of acrylic bone cement embedded with microencapsulated 2-octyl cyanoacrylate.

The water-reactive tissue adhesive 2-octyl cyanoacrylate (OCA) was microencapsulated in polyurethane shells and incorporated into Palacos R bone cement. The tensile and compressive properties of the composite material were investigated in accordance with commercial standards, and fracture toughness of the capsule-embedded bone cement was measured using the tapered double-cantilever beam geometry. Viability and proliferation of MG63 human osteosarcoma cells after culture with extracts from Palacos R bone cement, capsule-embedded Palacos R bone cement, and OCA were also analyzed. Incorporating up to 5 wt % capsules had little effect on the compressive and tensile properties of the composite, but greater than 5 wt % capsules reduced these values below commercial standards. Fracture toughness was increased by 13% through the incorporation of 3 wt % capsules and eventually decreased below the toughness of the capsule-free controls at capsule contents of 15 wt % and higher. The effect on cell proliferation and viability in response to extracts prepared from capsule-embedded and commercial bone cements were not significantly different from each other, whereas extracts from OCA were moderately toxic to cells. Overall, the addition of lower wt % of OCA-containing microcapsules to commercial bone cement was found to moderately increase static mechanical properties without increasing the toxicity of the material.

Occupational asthma and rhinitis caused by cyanoacrylate-based eyelash extension glues.

BACKGROUND: Eyelash extensions are applied on top of customers' lashes using instant glue containing cyano acrylate, known to cause occupational rhinitis (OR) and occupational asthma (OA). The number of beauty professionals applying these extensions is increasing due to their popularity. AIMS: To report on a case of OA with OR and a case of OR attributable to lash extension glue and to evaluate respiratory exposure in lash extension work. METHODS: Two beauty professionals with suspected OA and/or OR underwent inhalation challenge, including both control challenge and work-mimicking challenges using the lash extension glue, each with a 24-h follow-up. Volatile organic compounds (VOCs) present were assessed during the lash extension glue challenge. The glues were analysed for their (meth)acrylate content. RESULTS: Both beauty professionals (case 1 and case 2) applied lash extensions regularly for several hours per day as part of their work and had work-related rhinitis. Case 1 had a longer history of lash extension work and also had asthmatic symptoms. The first lash extension glue challenge was negative in both cases, but positive OR reactions were detected in the second test. Case 1 also had a late asthmatic reaction. During the lash extension glue challenge, VOC were present in total concentrations below the irritant threshold and ethylcyanoacrylate (ECA) was detected in a concentration of 0.4mg/m(3). Chemical analysis of the glues revealed ECA was the major component. CONCLUSIONS: Application of eyelash extensions using small amounts of cyanoacrylate-based glues can cause OA and OR.

Cytotoxicity testing of methyl and ethyl 2-cyanoacrylate using direct contact assay on osteoblast cell cultures.

PURPOSE: Cyanoacrylate has been used as a commercial tissue adhesive. Recently, ethyl 2-cyanoacrylate has been suggested for the fixation of onlay autogenous bone graft. However, ethyl 2-cyanoacrylate must be biocompatible with bone tissue. This study evaluated the cytotoxicity of cyanoacrylate adhesives using a direct contact assay on human oral osteoblast cells. MATERIALS AND METHODS: Osteoblastic cells derived from human alveolar bone of the mandible were cultured with or without cyanoacrylate. The CA1 group contained methyl 2-cyanoacrylate, the CA2 group contained ethyl 2-cyanoacrylate, and the CA3 group did not contain cyanoacrylate (control). This study investigated cell morphology, which included the inhibition zone, and cytotoxicity was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, which was measured as optical density. Data from the MTT assay were tested statistically using SigmaStat 3.5. RESULTS: Dead cells found around the CA1- and CA2-treated cells constituted inhibitory zones that varied from 200 to 500 µm. There was no inhibitory zone in the CA3 group. Cell viability evaluated by the MTT assay showed that the CA2 and CA3 optical densities were not significantly different. The CA1 optical densities differed significantly from the CA3 optical densities. CONCLUSIONS: Within the limits of this study, the MTT method supported the conclusion that ethyl 2-cyanoacrylate is biocompatible according to a direct contact assay on human osteoblast cell cultures and suggests its usefulness in bone graft fixation.

Evaluation of the histologic reactions to commonly used suture materials in the skin and musculature of ball pythons (Python regius).

OBJECTIVE: To evaluate histologic reactions to 8 suture materials and cyanoacrylate tissue adhesive (CTA) in the musculature and skin of ball pythons. ANIMALS: 30 hatchling ball pythons. PROCEDURES: In each snake, ten 1-cm skin incisions were made (day 0). At 8 sites, a suture of 1 of 8 materials was placed in the epaxial musculature, and the incision was closed with the same material. One incision was closed by use of CTA. No suture material was placed in the tenth incision, which was allowed to heal by second intention (negative control). Snakes (n = 5/group) were euthanized for harvest of treatment-site tissues at days 3, 7, 14, 30, 60, and 90. Skin and muscle sections were examined microscopically and assigned a subjective score (0 to 4) for each of the following: overall severity of inflammation, fibrosis, number of macrophages, number of granulocytes, number of perivascular lymphocytes, and degree of suture fragmentation. RESULTS: Subjective score analysis revealed that CTA did not cause a significant inflammatory response, compared with the negative control. All suture materials caused significantly more inflammation over all time points; for all suture materials, inflammatory response scores were significantly higher than values for the negative control 90 days after implantation. No sutures were completely absorbed by the end of the study period, and several sutures appeared to be in the process of extrusion. CONCLUSIONS AND CLINICAL RELEVANCE: In snakes, CTA can be used to close small superficial incisions or lacerations with minimal inflammatory response, and sutures may undergo extrusion from tissues prior to complete absorption.

Cytotoxicity and cellular uptake of newly synthesized fucoidan-coated nanoparticles.

The aim was to synthesize and characterize fucoidan-coated poly(isobutylcyanoacrylate) nanoparticles. The nanoparticles were prepared by anionic emulsion polymerization (AEP) and by redox radical emulsion polymerization (RREP) of isobutylcyanoacrylate using fucoidan as a new coating material. The nanoparticles were characterized, and their cytotoxicity was evaluated in vitro on J774 macrophage and NIH-3T3 fibroblast cell lines. Cellular uptake of labeled nanoparticles was investigated by confocal fluorescence microscopy. Results showed that both methods were suitable to prepare stable formulations of fucoidan-coated PIBCA nanoparticles. Stable dispersions of nanoparticles were obtained by AEP with up to 100% fucoidan as coating material. By the RREP method, stable suspensions of nanoparticles were obtained with only up to 25% fucoidan in a blend of polysaccharide composed of dextran and fucoidan. The zeta potential of fucoidan-coated nanoparticles was decreased depending on the percentage of fucoidan. It reached the value of -44 mV for nanoparticles prepared by AEP with 100% of fucoidan. Nanoparticles made by AEP appeared more than four times more cytotoxic (IC(50) below 2 µg/mL) on macrophages J774 than nanoparticles made by RREP (IC(50) above 9 µg/mL). In contrast, no significant difference in cytotoxicity was highlighted by incubation of the nanoparticles with a fibroblast cell line. On fibroblasts, both types of nanoparticles showed similar cytotoxicity. Confocal fluorescence microscopy observations revealed that all types of nanoparticles were taken up by both cell lines. The distribution of the fluorescence in the cells varied greatly with the type of nanoparticles.

Cyanoacrylate in nerve repair: transient cytotoxic effect.

Cyanoacrylate adhesive has been suggested as an alternative to suturing when repairing severed peripheral nerves. The authors examined the cytotoxic effect of ethyl-cyanoacrylate on the human neuroblastoma cell line SH-SY5Y and compared it with the effects of butyl-cyanoacrylate (Histoacryl), an adhesive approved for skin closure. Ethyl-cyanoacrylate or butyl-cyanoacrylate was applied in confluent SH-SY5Y cultures. Immediately, at 24h and at 7, 14, 21 and 28 days, cultures were photographed and analysed digitally. At corresponding intervals, cell death was quantified using a (51)Cr release assay. In cultures exposed to ethyl-cyanoacrylate or butyl-cyanoacrylate, cell death was observed predominantly in conjunction with the adhesive, causing a halo devoid of cells. Surviving cells showed neurodegenerative properties with loss of neuritis and reduction of body size up to 3 days post exposure. The inhibition halo diminished over time in both groups and at 28 days cells reached the margin of the adhesive in the ethyl-cyanoacrylate group. (51)Cr assay indicated significant cell death in exposed cultures, which rapidly decreased during the first 14 days. No significant differences were found between the adhesives. This study demonstrates that ethyl-cyanoacrylate and butyl-cyanoacrylate have a transient cytotoxic effect, which may explain the promising results when using cyanoacrylate for nerve repair.

A comparison of a cyanoacrylate [corrected] glue (Glubran) vs. fibrin sealant (Tisseel) in experimental models of partial pulmonary resection and lung incision [corrected] in rabbits.

INTRODUCTION: Bronchopleural fistulas (BPF) and air leaks (AL) present major complications after pulmonary resection. Various tissue sealants have been proposed for their prevention, e.g., fibrin sealant (FS) and cyanoacrylate glues (CA). Contrary to the safety record of FS, substantial side effects such as foreign body reaction and impaired tissue integration have been reported for CA. This study compares the sealing efficacy and biocompatibility as well as side effects of FS and CA in experimental partial pulmonary resection and lung incision in rabbits. METHODS: 26 New Zealand white rabbits (3 kg) were randomized to one of the three groups: partial pulmonary resection (A, acute model; n = 7 FS/ 7CA), lung incision [2 (B; n = 3 FS/ 3 CA)], and 14-day observation period (C; n = 3 FS/ 3 CA). In all groups (A, B, and C), FS was considered as control and CA as treatment. Surgery was carried out in general anaesthesia and mechanical ventilation. For partial lung resection a median thoracotomy was performed and the apex of the left median lobe was resected and the parenchymal surface covered with 0.09 ml of FS and CA. The thoracic cavity was filled with ringer solution after 5 minutes. The inspiratory minute volume (IMV) was increased by 0.02 l after every 4th inspiration. In groups B and C, a left lateral thoracotomy was performed in the 4th intercostal space and the left median lobe was incised with a scalpel. The incision was covered with 0.5 ml of FS or CA. At autopsy (B and C) the operation site was assessed macroscopically. Histology was performed in all animals. RESULTS: In terms of sealing purposes, FS and CA yielded comparable results in all groups. CA elicited a substantial increase of tissue temperature in the acute phase immediately after application (A). After 14 days CA residues were found, whereas FS was completely degraded. Histology showed a pronounced inflammatory response to CA but not to FS. We conclude that although the effect of airtight sealing was equally satisfying, our results emphasize that FS is preferable to CA for the prevention of BPF and AL due to superior biocompatibility and degradability. Longterm effects of CA residues on pulmonary tissue require further experimental testing.