The aplication of cyanoacrilate surgical glue on skin suture in rats

Dissolving microneedles for long-term storage and transdermal delivery of extracellular vesicles

Extracellular vesicles (EVs) have shown great potential in disease diagnosis and treatment; however, their clinical applications remain challenging due to their unsatisfactory long-term stability and the lack of effective delivery strategies. In this study, we prepared human adipose stem cell-derived EV (hASC-EV)-loaded hyaluronic acid dissolving microneedles (EV@MN) to investigate the feasibility of EVs for their clinical applications. The biological activities of the EVs in this formulation were maintained for more than six months under mild storage conditions, especially at temperatures lower than 4 °C. Moreover, the EV@MN enabled precise and convenient intradermal delivery for sustained release of EVs in the dermis layer. Therefore, EV@MN significantly improved the biological functions of hASC-EVs on dermal fibroblasts by promoting syntheses of proteins for the extracellular matrix such as collagen and elastin, enhancing fibroblast proliferation, and regulating the phenotype of fibroblast, compared with other administration methods. This research revealed a possible and feasible formulation for the clinical application of EVs.

Forward Wound Closure with Regenerated Silk Fibroin and Polylysine-Modified Chitosan Composite Bioadhesives as Dressings

Wound dressing has been used for decades to be effective for accelerating skin wound healing. However, practical applications are still limited due to their lower cell affinity, tissue adhesiveness, and biocompatibility. Natural polymers are the important biomaterials because of their excellent biodegradability, biocompatibility, and low immunogenicity. In this work, the composite bioadhesives (PLS-CS/RSF) were prepared from regenerated silk fibroin (RSF) and polylysine-modified chitosan (PLS-CS) that were cross-linked by Ca²⁺ ions. The adhesion property tests showed that the PLS-CS/RSF exhibited excellent bonding potentials for various substrates, and the adhesive strength was up to 70 kPa for isolated porcine skin by the extension test. The as-prepared PLS-CS/RSF was nontoxic, displayed obvious antibacterial effects against Staphylococcus aureus and Escherichia coli in vitro, and their bacteriostasis rates were 100% after 120 min treatment. In addition, the PLS-CS/RSF exhibited favorable cytocompatibility by cell counting kit-8 assay. The animal model of wound closure results showed that PLS-CS/RSF can promote wound closure and the integrity of wound healing, inhibiting the secretion of inflammatory factor and tumor necrosis factor and stimulating vascular factor and α-smooth muscle actin to the release of vascular growth factor and promote angiogenesis during the process of wound healing by immunohistochemical assay.

Use of cyanoacrylate-based surgical adhesives associated to the macroporous tape in skin synthesis in rats

PURPOSE

To compare the use of new cyanoacrylate surgical adhesive associated with macroporous tapes in cutaneous synthesis.

METHODS

Male Wistar rats with a longitudinal incision of 4cm were used on the back, divided into four groups: GI used octyl-cyanoacrylate (Dermabond®), GII used N-2-butylcyanoacrylate, GIII used octyl-cyanoacrylate and macroporous tape and GIV used N-2-butyl cyanoacrylate and macroporous tape. On the fourteenth day, the rats were submitted to euthanasia, were divided in two parts, and a layer of skin subcutaneous tissue through an area of operative healing was removed. One part was submitted to the study of rupture strength with the use of tensiometer, and in the other part histological examination was performed.

RESULTS

No force test was similar between groups I and II, being different from groups III and IV (P <0.001), which were identical to each other (P> 0.05). The units were compared among the studied groups, and they were different with the use of macroporous tapes (P> 0.05).

CONCLUSIONS

The purpose of macroporous tapes is associated with CA adhesives in cutaneous tissues that provide more resistant scars. The use of a combination of macroporous tapes leads to complete re-epithelialization, without provoking foreign body reaction, has hemostatic properties and does not cause an absorptive reaction.

[Application of adhesive compositions in surgery (in Russian only)]

New adhesive compositions will almost completely prevent leakage of surgical sutures and undue tissue damage, improve healing and postoperative rehabilitation. At present time there is no universal type of bioadhesives that is suitable for all tissues and types of sutures because of various surgeries and their specificity. The article describes the advantages and disadvantages of all common types of bioadhesives, as well as the ways to overcome their disadvantages.

Histological analysis of biocompatibility of different surgical adhesives in subcutaneous tissue

The focus of this study was to test the hypothesis that there would be no difference between the biocompatibility of cyanoacrylate-based adhesives in rat subcutaneous tissues. In total, 60 male Wistar rats were used, and divided into four groups (n = 15): Group C (control, PVA-polyvinyl alcohol sponge), Group NO (N-butyl-2-octylcyanoacrylate), Group NH (n-hexyl-cyanoacrylate), and Group EC (Ethyl-cyanoacrylate). The animals were sacrificed after time intervals of 7, 15, and 30 days and tissues were analyzed under optical microscope as regards the events of inflammatory infiltrate, edema, necrosis, granulation tissue, giant cells, young fibroblasts, and collagen formation. The results were statistically analyzed by the Kruskal-Wallis and Dunn tests (p < .05). Significant inflammatory infiltrate was shown for all the adhesives in the time intervals of 7 (p = .004) and 15 days (p = .003). In the time interval of 30 days, moderate inflammatory infiltrate was observed in Groups NH and EC, with significant difference from Control (p = .001). The quantity of collagen fibers in all the experimental groups showed significant difference compared with Control in the time intervals of 7 (p = .002) and 15 days (p = .001), at 30 days only Group EC showed a smaller quantity of collagen fibers in comparison with Control (p = .001). The hypothesis was rejected. The adhesive N-butyl-2-octylcyanoacrylate had less influence on the inflammatory intensity of multinucleated giant cells. Ethyl-cyanoacrylate demonstrated the lowest level of biocompatibility among the adhesives, but its use in clinical practice may be promising for coaptation of smaller edges of superficial tissue. Surgical adhesives were shown to be feasible for clinical use in substitution of conventional suturing. Ethyl-cyanoacrylate should be used with caution due to its greater influence on tissues.

Pain perception following epithelialized gingival graft harvesting: a randomized clinical trial

OBJECTIVES

The aim of this study was to compare the effects of a hemostatic collagen sponge and a collagen sponge sealed with a bio-adhesive material on the palatal donor sites with the purpose of minimizing postoperative pain after epithelialized gingival graft (EGG) harvesting.

MATERIAL AND METHODS

The present study consisted of 44 EGGs harvested in 44 patients. In the control group, a hemostatic collagen sponge was applied over the palatal wound, while the test group was treated with additional cyanoacrylate. Patients were observed for 14 days, evaluating the pain level by using the visual analogic scale. The consumption of analgesic during the postoperative period, the willingness for retreatment and the characteristic of the graft were also analyzed.

RESULTS

Statistically significant differences in pain perception were found between test and control groups in each of the studied days (p < 0.01). Analgesic consumption was lower in the test group (p < 0.01). Graft width < 14 mm was found to be associated with lower discomfort (p < 0.01).

CONCLUSIONS

Adding an additional layer of cyanoacrylate over a hemostatic collagen sponge on the palatal wound following EGG harvesting was found to be successful in minimizing the postoperative discomfort and the need for analgesics.

CLINICAL RELEVANCE

Postoperative pain after palatal tissue harvesting can be successfully minimized if the donor site open wound is protected with an external layer of cyanoacrylate over a collagen sponge.