Evaluation of n-Butyl Cyanoacrylate Adhesive in Rat Subcutaneous Tissue

Background Tissue adhesives have been widely used for wound closure, especially in children, because they are painless, fast, and easy to use and result in minimal scarring.Objective To analyze the biocompatibility of an adhesive based on n-butyl-cyanoacrylate in the subcutaneous tissue of rats.Materials and Methods Two surgical sites were prepared (approximately 3 cm apart): one on the left side of the animal and the other on the right side); polyethylene tubes were implanted in each surgical site. The tube on the left was filled with n-butyl-cyanoacrylate (treated group) and the tube on the right side was unfilled (control group). After 7, 30, and 120 days, the animals were killed, and the specimens were processed for histologic analysis.Results No significant inflammatory reaction occurred in the treated group, showing results similar to the control group.Conclusion This adhesive based on n-butyl-cyanoacrylate is biocompatible in the subcutaneous tissue of rats.

Utilization of Ethyl Cyanoacrylate and 2-Octyl Cyanoacrylate Adhesives for Autogenous Bone Graft Fixation: Histomorphometric Study in Rats

The present study analyzes the repair process of autogenous bone graft in a block fixed with ethyl cyanoacrylate and 2-octyl cyanoacrylate adhesives in rat calvaria. Forty-eight rats, divided into 3 groups, received round osteotomies at the right parietal bone for the attainment of autogenous bone graft fragment, which was fixed at the opposite side to the donor site with ethyl cyanoacrylate (ethyl group) and 2-octyl cyanoacrylate (octyl group) adhesives. In the control group, bone fragment was only juxtaposed at the parietal bone surface without any fixation material. The animals were euthanized after 10 and 60 postoperative days. The calvariae were processed in a laboratory for the attainment of slides stained through the hematoxylin and eosin technique for histological and histometric analysis. The qualitative analysis showed a discrete inflammatory infiltrate in the control group and moderate inflammatory infiltrate in the ethyl and octyl groups at the 10-day period, which remained at the 60-day period, mainly in the octyl group. The bone fragment remained bonded to the recipient site through the adhesive, but graft incorporation was not observed in any of the specimens. Resorption was higher in the octyl group followed by the ethyl and control groups, both at the 10-and 60-day periods, but with no statistical significance (P < .05). Although promoting graft fixation and its maintenance at the recipient site, both studied adhesives did not allow the graft incorporation, producing a localized and discrete inflammatory reaction, which persisted at 60 days, being more intense in the octyl cyanoacrylate group.

Histomorphometric analysis of the repair process of autogenous bone grafts fixed at rat calvaria with cyanoacrylate

Objective: The purpose of this study was to perform histological and histometric analyses of the repair process of autogenous bone grafts fixed at rat calvaria with ethyl-cyanoacrylate adhesive. Material and Methods: Thirty-two rats were divided into two groups (n=16), Group I - Control and Group II - Adhesive. Osteotomies were made at the right parietal bone for graft obtainment using a 4-mm-diameter trephine drill. Then, the bone segments were fixed with the adhesive in the parietal region of the opposite side to the donor site. After 10 and 30 days, 8 animals of each group were euthanized and the calvarias were laboratorially processed for obtaining hematoxylin and eosin-stained slides for histological and histometric analyses. Results: An intense inflammatory reaction was observed at the 10-day period. At 30 days, this reaction was less intense, despite the presence of adhesive at the recipient-site/graft interface. Graft incorporation to the recipient site was observed only at the control group, which maintained the highest graft size at 10 and 30 days. Conclusions: Although the fragment was stable, the presence of adhesive in Group II did not allow graft incorporation to the recipient site, determining a localized, discrete and persistent inflammatory reaction.

Adesivos à base de cianoacrilato para síntese de tecido mole

FUNDAMENTOS - Adesivos teciduais têm sido muito usados para síntese de ferida, em função de ser um método indolor, rápido e de fácil execução. OBJETIVOS -Analisar e comparar compatibilidade dos adesivos, etil- cianoacrilato (Super Bonder) e butilcianoacrilato (Histoacryl), e a reparação de incisões em dorso de ratos entre o fio de sutura e os respectivos adesivos. MÉTODOS - Foram usados 15 ratos. Realizaram-se duas lojas cirúrgicas no dorso. em cada uma, foi implantado um tubo de polietileno (10mm x 1mm), os quais foram preenchidos com os adesivos Super Bonder (lado direito) e Histoacryl (lado esquerdo). As incisões, do lado esquerdo, foram coaptadas com Super Bonder, e as do lado direito, com Histoacryl. Uma incisão mediana, entre as duas incisões,foi realizada e suturada com fio de seda. Os animais foram mortos, depois de 7(sete), 35(trinta) e 120 (cento e vinte dia) dias. RESULTADOS: Os adesivos usados, no presente estudo, não promoveram reação inflamatória, quando usados para síntese das incisões. Porém, estes adesivos, quando implantados no subcutâneo, promoveram reação inflamatória até 120 (cento e vinte dia) dias, no entanto, a reação é mais intensa com Histoacryl. CONCLUSÕES: Super Bonder e Histoacryl permitem o processo cicatricial dos tecidos incisados; facilitam a sutura das incisões. Desta forma, estes podem ser utilizados para sínteses de feridas, lacerações ou incisões cutâneas.

Effects of fibrin adhesive material (Tissucol) on alveolar healing in rats under stress.

The effects of Tissucol on alveolar healing following stress were evaluated histologically, comparing three groups of 28 male albino rats each. Stress was applied and their right upper incisors were extracted. Group A served as an empty control site. In Group B, Tissucol was applied into the alveolar cavity. Group C received local antifibrinolytic treatment (alveolar irrigation with epsilon-aminocaproic acid solution) before implant of Tissucol into the tooth socket. Four animals in each group were killed at 1, 3, 6, 9, 15, 21 and 24 days after surgery. Results showed that: 1) Tissucol did not interfere with connective and osseous tissue formation; 2) Tissucol allowed new bone formation; 3) Tissucol residues in Group B in sections of 24-day specimens did not impair healing; 4) Tissucol was usually completely resorbed and healing was complete 24 days after surgery in Group C.

In vitro antimicrobial efficiency of a mouthwash containing triclosan/gantrez and sodium bicarbonate

Several antiseptic substances have been used as adjuncts to routine mechanical procedures of oral hygiene, based on their antimicrobial effects. The objective of this study was to assess in vitro the antimicrobial efficiency of 2 mouthwash containing Triclosan/Gantrez and sodium bicarbonate in comparison to both positive and negative controls. Standard strain samples of Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus and Bacillus subtilis were used. Samples of Streptococcus mutans and Gram-negative bacilli were collected from 20 volunteers (10 with a clinically healthy periodontium and 10 presenting biofilm-associated gingivitis). Evaluation of the antimicrobial activity was performed by determining the minimal inhibitory concentration (MIC). The results indicated that the test solution inhibited the growth of both Gram-negative and Gram-positive microorganisms from the volunteers' saliva as well as that of the standard strains at the MIC dilution of 1:20, whereas the MIC dilution of 0.12% chlorhexidine against the same bacteria was 1:80. Thus, even though the tested mouthrinse solution presented an in-vitro antimicrobial activity superior to that of a placebo, it was inferior to that of chlorhexidine.

Fator de crescimento nervoso em cola de fibrina no reparo término-lateral de nervos em ratos

Purpose: To determine the effects of end-to-side nerve repair performed only with fibrin glue containing nerve growth in rats. Methods: Seventy two Wistar rats were divided into six equal groups: group A was not submitted to nerve section; group B was submitted to nerve fibular section only. The others groups had the nerve fibular sectioned and then repaired in the lateral surface of an intact tibial nerve, with different procedures: group C: ETS with sutures; group D: ETS with sutures and NGF; group E: ETS with FG only; group F: ETS with FG containing NGF. The motor function was accompanied and the tibial muscle mass, the number and diameter of muscular fibers and regenerated axons were measured. Results: All the analyzed variables did not show any differences among the four operated groups (p>0.05), which were statistically superior to group B (p<0.05), but inferior to group A (p>0.05). Conclusion: The end-to-side nerve repair presented the same recovery pattern, independent from the repair used, showing that the addition of nerve growth factor in fibrin glue was not enough for the results potentiating.

Repair of superficial osteochondral defects with an autologous scaffold-free cartilage construct in a caprine model: implantation method and short-term results

OBJECTIVE: To compare four different implantation modalities for the repair of superficial osteochondral defects in a caprine model using autologous, scaffold-free, engineered cartilage constructs, and to describe the short-term outcome of successfully implanted constructs. METHODS: Scaffold-free, autologous cartilage constructs were implanted within superficial osteochondral defects created in the stifle joints of nine adult goats. The implants were distributed between four 6-mm-diameter superficial osteochondral defects created in the trochlea femoris and secured in the defect using a covering periosteal flap (PF) alone or in combination with adhesives (platelet-rich plasma (PRP) or fibrin), or using PRP alone. Eight weeks after implantation surgery, the animals were killed. The defect sites were excised and subjected to macroscopic and histopathologic analyses. RESULTS: At 8 weeks, implants that had been held in place exclusively with a PF were well integrated both laterally and basally. The repair tissue manifested an architecture similar to that of hyaline articular cartilage. However, most of the implants that had been glued in place in the absence of a PF were lost during the initial 4-week phase of restricted joint movement. The use of human fibrin glue (FG) led to massive cell infiltration of the subchondral bone. CONCLUSIONS: The implantation of autologous, scaffold-free, engineered cartilage constructs might best be performed beneath a PF without the use of tissue adhesives. Successfully implanted constructs showed hyaline-like characteristics in adult goats within 2 months. Long-term animal studies and pilot clinical trials are now needed to evaluate the efficacy of this treatment strategy.

Treatment of venous ulcers with surgical adhesives derived from snake venom

A Brazilian dictionary states that "ulcer", from the Latin word ulcuserise, is a superficial lesion on skin or mucous membrane characterized by an inflammatory process and loss of tissue. Ulcers are a relatively frequent problem that may be worsen by infection or long-time duration. In these cases, they can represent a serious public health issue, since the increased case number contributes to the burden on the public health service. In recent decades, wound treatment has advanced in technological and scientific aspects regarding both development of new products and techniques. Ongoing research in this area is providing new products for wound treatment. Among newly tested substances that have presented successful results is fibrin glue, a snake venom derivative that promotes reduction of infection and edema as well as bleeding control and pain decrease. Thus, the present study aimed to evaluate fibrin glue effects on ulcers of venous origin in 24 patients that were divided into two groups. The first one (G1) consisted of 11 patients treated without the adhesive while the second group (G2) was composed of 13 persons who were under therapy with the adhesive. The results of this study revealed that patients treated with fibrin glue evolved to a satisfactory healing when compared to the other group. Therefore, fibrin glue is an appropriate alternative for treating leg ulcers with several advantages: easy application, less pain, early hospital discharge, not transmiting diseases, lower cost than the adhesive currently available in Brazil and, finally, it is a Brazilian technology.

Adhesives and interfacial phenomena in wound healing

This chapter deals initially with the underlying principles of adhesion and adhesives and the understanding of interfacial behaviour. This provides a basis upon which to understand biological interactions (. Chapter 12). The two broad types of adhesive materials encountered in wound healing are pressure-sensitive adhesives (PSA) and tissue sealants. The function of pressure-sensitive adhesives is to form an adhesive bond between tissue and biomaterial under the influence of pressure. Tissue sealants are liquids that convert to solid form at the tissue surface and in so doing form either an effective seal against fluid leakage or a bond between adjacent tissue surfaces. The different requirements and characteristics of these systems are discussed. © 2011 Woodhead Publishing Limited All rights reserved.

Physical and biological properties of a novel siloxane adhesive for soft tissue applications

The aim of this study was to investigate the adhesive properties of an in-house amino-propyltrimethoxysilane-methylenebisacrylamide (APTMS-MBA) siloxane system and compare them with a commercially available adhesive, n-butyl cyanoacrylate (nBCA). The ability of the material to perform as a soft tissue adhesive was established by measuring the physical (bond strength, curing time) and biological (cytotoxicity) properties of the adhesives on cartilage. Complementary physical techniques, X-ray photoelectron spectroscopy, Raman and infrared imaging, enabled the mode of action of the adhesive to the cartilage surface to be determined. Adhesion strength to cartilage was measured using a simple butt joint test after storage in phosphate-buffered saline solution at 37°C for periods up to 1 month. The adhesives were also characterised using two in vitro biological techniques. A live/dead stain assay enabled a measure of the viability of chondrocytes attached to the two adhesives to be made. A water-soluble tetrazolium assay was carried out using two different cell types, human dermal fibroblasts and ovine meniscal chondrocytes, in order to measure material cytotoxicity as a function of both supernatant concentration and time. IR imaging of the surface of cartilage treated with APTMS-MBA siloxane adhesive indicated that the adhesive penetrated the tissue surface marginally compared to nBCA which showed a greater depth of penetration. The curing time and adhesion strength values for APTMS-MBA siloxane and nBCA adhesives were measured to be 60 s/0.23 MPa and 38 min/0.62 MPa, respectively. These materials were found to be significantly stronger than either commercially available fibrin (0.02 MPa) or gelatin resorcinol formaldehyde (GRF) adhesives (0.1 MPa) (P <0.01). Cell culture experiments revealed that APTMS-MBA siloxane adhesive induced 2% cell death compared to 95% for the nBCA adhesive, which extended to a depth of approximately 100-150 μm into the cartilage surface. The WST-1 assay demonstrated that APTMS-MBA siloxane was significantly less cytotoxic than nBCA adhesive as an undiluted conditioned supernatant (P <0.001). These results suggest that the APTMS-MBA siloxane may be a useful adhesive for medical applications. © VSP 2005.

Biomaterial interactions with compromised tissue surfaces

This thesis is concerned with the nature of biomaterial interactions with compromised host tissue sites. Both ocular and dermal tissues can be wounded, following injury, disease or surgery, and consequently require the use of a biomaterial. Clear analogies exist between the cornea/tear film/contact lens and the dermal wound bed/wound fluid/skin adhesive wound dressing. The work described in this thesis builds upon established biochemistry to examine specific aspects of the interaction of biomaterials with compromised ocular and dermal tissue sites, with a particular focus on the role of vitronectin. Vitronectin is a prominent cell adhesion glycoprotein present in both tear fluid and wound fluid, and has a role in the regulation and upregulation of plasmin. The interaction of contact lenses with the cornea was assessed by a novel on-lens cell-based vitronectin assay technique. Vitronectin mapping showed that vitronectin-mediated cell adhesion to contact lens surfaces was due to the contact lens-corneal mechanical interaction rather than deposition out of the tear film. This deposition is associated predominantly with the peripheral region of the posterior contact lens surface. The locus of vitronectin deposition on the contact lens surface, which is affected by material modulus, is potentially an important factor in the generation of plasmin in the posterior tear film. Use of the vitronectin mapping technique on ex vivo bandage contact lenses revealed greater vitronectin-mediated cell adhesion to the contact lens surfaces in comparison to lenses worn in the healthy eye. The results suggest that vitronectin is more readily deposited from the impaired corneal tissue bed than the intact healthy tissue bed. Significantly, subjects with a deficient tear film were found to deposit high vitronectin-mediated cell adhesion levels to the BCL surface, thus highlighting the influence of the contact lens-tissue interaction upon deposition. Biomimetic principles imply that adhesive materials for wound applications, including hydrogels and hydrocolloids, should closely match the surface energy parameters of skin. The surface properties of hydrocolloid adhesives were found to be easily modified by contact with siliconised plastic release liners. In contrast, paper release liners did not significantly affect the adhesive surface properties. In order to characterise such materials in the actual wound environment, which is an extremely challenging task, preliminary considerations for the design of an artificial wound fluid model from an animal serum base were addressed.

The Expanded Human Kallikrein (KLK) gene family : genomic organisation, tissue specific expression and potential functions

The tissue kallikreins are serine proteases encoded by highly conserved multigene families. The rodent kallikrein (KLK) families are particularly large, consisting of 13 26 genes clustered in one chromosomal locus. It has been recently recognised that the human KLK gene family is of a similar size (15 genes) with the identification of another 12 related genes (KLK4-KLK15) within and adjacent to the original human KLK locus (KLK1-3) on chromosome 19q13.4. The structural organisation and size of these new genes is similar to that of other KLK genes except for additional exons encoding 5 or 3 untranslated regions. Moreover, many of these genes have multiple mRNA transcripts, a trait not observed with rodent genes. Unlike all other kallikreins, the KLK4-KLK15 encoded proteases are less related (25–44%) and do not contain a conventional kallikrein loop. Clusters of genes exhibit high prostatic (KLK2-4, KLK15) or pancreatic (KLK6-13) expression, suggesting evolutionary conservation of elements conferring tissue specificity. These genes are also expressed, to varying degrees, in a wider range of tissues suggesting a functional involvement of these newer human kallikrein proteases in a diverse range of physiological processes.