Objective: Obteinment and characterizing polymeric nanocapsules of simvastatin (SV), and investigating their action in an experimental model of peritoneal fibrosis induced in a rat by the infusion of peritoneal dialysis (PD) solution. Methods: Poly (ε-caprolactone) nanocapsules containing SV (NC-SV) were prepared by interfacial deposition of a preformed polymer. A suspension of nanoparticles with no drug was prepared as negative control. The average particle size and polydispersity index were measured by photon correlation spectroscopy. The morphological and surface evaluation of prepared nanocapsules was performed using field emission scanning electron microscopy. The ultra-high performance liquid chromatography with photodiode array detection method was used to evaluate the drug encapsulation efficiency. The release profiles of SV from polymeric nanocapsules were obtained by dialysis diffusion technique. The Animal Study was performed in a total of 48 male Wistar rats (Rattus norvegicus) divided in four groups: Sham, PD group, SV group, and Simvastatin-loaded nanocapsules group (NC-SV). After 28 days, tissue samples were surgically removed from the abdominal to perform histological and immunohistochemistry analysis. The statistical analysis was performed by one-way ANOVA followed by Bonferroni test, or by Kruskal–Wallis. Results: NC-SV presented suitable particle parameters with a mean particle size of 332 nm, and an encapsulation efficiency of 99.87±0.46%. The expression of tumor necrosis factor-alpha (TNF-α) was significantly different in NC-SV group. Conclusion: SV-loaded nanocapsules for controlled drug delivery were suitably prepared. This nanoformulation remarkable decreased the TNF-α tissue expression even at low SV dose in a chronic PD model.

- BACKGROUND: Proper fixation of the surgical mesh determines the success of a herniorrhaphy. Understanding the inflammatory response and the mechanical properties of the mesh helps to define whether a fixation method is superior. AIM: This study aimed to evaluate the healing of defects in the abdominal wall of rats, comparing the repair of macroporous polypropylene meshes fixed with surgical glue and polypropylene thread. METHODS: In 20 Wistar rats, a defect was produced in the abdominal wall, with the integrity of the parietal peritoneum. For correction, the meshes were fixed with surgical glue (2-octyl cyanoacrylate) (subgroup C1), or polypropylene suture (subgroup C2). The two subgroups of 10 animals were euthanized on the 90th postoperative day, and the fragments of the abdominal wall were submitted to macroscopic, histological, and tensiometric analysis. RESULTS: Macroscopic analysis did not show any abnormalities. Tensiometry on the 90th postoperative day in subgroup C1 showed mean rupture tension of 28.47N and in subgroup C2 32.06N (p=0.773). The inflammatory process score revealed that both groups are in the subacute phase (p=0.380). CONCLUSION: The fixation of a polypropylene macroporous mesh to repair an abdominal wall defect can be performed with surgical glue (2-octyl cyanoacrylate) or polypropylene suture, both methods being equally effective.