# Topical over Dermal Versus Transdermal Application of Cyanoacrylate in Wound Synthesis and Its Effects on Healing—Experimental Study

## TL;DR

This study compares how applying cyanoacrylate adhesives on or through the skin affects wound healing in rats, finding that application method impacts healing more than adhesive type.

## Contribution

The study introduces a novel comparison of topical over dermal versus transdermal application methods of cyanoacrylate adhesives in wound healing.

## Key findings

- Transdermal application showed improved mononuclear cell activity but higher inflammation and oxidative stress.
- Topical over dermal application resulted in better-aligned wound edges and collagen production for scar resolution.
- Application technique had a greater impact on healing than the type of cyanoacrylate monomer used.

## Abstract

Cyanoacrylate-based adhesives are commonly used for wound closure due to their short synthesis time, aesthetic outcomes, and minimal discomfort. However, reported adverse effects include the release of cytotoxic metabolites, inflammation, and foreign body reactions. This study evaluated and compared the effectiveness of three cyanoacrylate-based adhesives for skin incision closure in Rattus norvegicus. The subjects were divided into three groups based on the type of monomer: G1 (n-2-ethyl-cyanoacrylate), G2 (n-2-butyl-cyanoacrylate), and G3 (n-2-octyl-cyanoacrylate). Each animal received two 2 cm paramedian incisions, which were closed using either a topical over dermal (OD) or a topical transdermal (TD) application, resulting in two subgroups per group. Wounds were evaluated on postoperative days 3, 7, 14, and 21 to compare the different monomers and application techniques. Assessment of the inflammatory infiltrate revealed differences in polynuclear cells between the TD and OD on days 3 and 7, while TD demonstrated improved results in mononuclear cells at all time points. Sustained inflammatory processes and foreign body reactions were observed. Quantification of tumor necrosis factor (TNF-α) and thiobarbituric acid reactive substances (TBARS) indicated that TD maintained stability throughout the assessment periods, though it exhibited higher values than OD from days 7 to 21. These higher values were associated with a foreign body reaction and increased oxidative stress. Regarding tissue formation, OD produced more aligned wound edges, supporting the production of types I and III collagen and improving scar resolution compared to TD. Our findings indicate that the patch application technique has a greater impact on healing than the size of the cyanoacrylate monomer.