Bruno Morandi Pires

Impregnation of implantable polypropylene mesh with S-nitrosoglutathione-loaded poly(vinyl alcohol)

Clinical complications of implantable polypropylene (PP) meshes used to repair urinary incontinence and vaginal prolapse may be associated with their low surface energy and consequent poor tissue integration. For improving tissue integration, we impregnated monofilament PP meshes with physically crosslinked poly(vinyl alcohol) (PVA), resulting in PVA deposits tightly attached inside the knot spaces of the PP knit. While preserving the mesh porosity, the PVA deposits acted as an array of hydrophilic regions leading to a great increase in the overall mesh wettability, reflected by a contact angle decrease from 111 to ca. 66°. The PVA deposits were also used as reservoirs for the local release of S-nitrosoglutathione (GSNO), a nitric oxide (NO) donor. Plain and impregnated PP meshes (1.0cm×1.0cm) were implanted in the subcutaneous tissue of 21 adult female Wistar rats. Histological analysis of the abdominal wall 21 days after the surgeries revealed lower edema and greater angiogenesis while a marked decrement of NOx concentration in the tissue surrounding the impregnated meshes was observed after 2 days. These results indicate that PVA and PVA/GSNO impregnation might be a new strategy for decreasing the frequency of mesh extrusion after PP mesh implants.

Stabilization of meso-tetraferrocenyl-porphyrin films by formation of composite with Prussian blue

Supramolecular systems based on porphyrin-ferrocene have attracted the attention to inorganic electrochemistry due to unique electronic properties and synergic behavior between porphyrin ring and peripheral ferrocene group. In order to improve the stability of the films of ferrocenyl-porphyrin on electrode’s surface, we used a combination of tetraferrocenylporphyrin and Prussian blue. The new structure formed was very stable and could be used in dopamine sensing, showing satisfactory analytical response comparable to other chemically modified electrodes the described in the literature.