Vantris® biocompatible, synthetic, non-biodegradable, easy to administer tissular bulking substance. Evaluation of local tissular reaction, localized migration and long-distance migration

M. PALADINI; R. PISANO; M. SCAGLIOTTI; R. SAMBUELLI; S. LOPEZ; A. GUIDI; J. MUÑOZ; V. ROSSETTI; M. CARNERERO; F. DE BADIOLA; D. M. BELTRAMO; R.V. ALASINO; I.D. BIANCO; O. GRIGUOL; D. VALLADARES

ARCHIVOS ESPANOLES DE UROLOGIA.

Archivos Españoles de Urologia S.A.U.

Lugar: Madrid; Año: 2008 vol. 61 p. 263 - 268

0004-0614

Abstract Biodegradable injectable bulking agents of animal origin present a fast rate of bioreabsorption and may cause an allergic reaction. Biodegradable elements of synthetic origin have a high rate of reabsorption after a year. Non-biodegradable agents of synthetic origin lead to the formation of a fibrotic capsule giving stability and long-term permanence. VANTRIS® is categorized in this last group; it belongs to the family of Acrylics, particles of polyacrylate polyalcohol copolymer immersed in a glycerol and water carrier. Molecular mass is very high and it comes in the form of a gel. When injected in soft tissues, this hydrogel causes a bulkiness that remains stable through time. The carrier is a 40% glycerol solution with a pH of 6. Once injected, the carrier is eliminated without metabolizing by the reticular system through the kidneys. Particles of this polyacrylate polyalcohol with glycerol are highly deformable by compression, and may be injected using a 23-gauge needle. 97% of particles are larger than 110 mm when extruded by this needle. The average size is 320 mm. Once implanted, particles adhere to tissues with minimum fibrosis. Particles of this new material are anionic with high superficial electronegativity, thus promoting a low cellular interaction and low fibrotic growth. The new polyacrylate polyalcohol copolymer with glycerol was tested for biocompatibility according to ISO 10993-1:2003 in vitro showing that they are not mutagenic for the Salmonella T. strains analyzed. The extract turned out to be no cytotoxic for cell lines in culture and non-genotoxic for mice.  In in vivo studies, acrylate did not cause sensitization in mice. The macroscopic reaction of tissue irritation was not significant in subcutaneous implants and in urethras of rabbits. 7 female dogs were injected transurethrally with VANTRIS® to evaluate short and long-term migration (13 weeks and 12 months respectively). 13 weeks and 12 months later no particles or signs of inflammation or necrosis are observed in any of the organs examined. To conclude, this new material meets the conditions of ideal tissue bulking material.