Vascular endothelial growth factor overexpression positively modulates the characteristics of periprosthetic tissue of polyurethane-coated silicone breast implant in rats.
BACKGROUND
Capsular contracture is one of the most common complications associated with silicone breast implants. The surface of the implant is one of the factors often associated with the occurrence of capsular contracture. In this study, the authors evaluated the differences in morphologic and molecular characteristics of the capsule formed around polyurethane-coated versus textured-surface silicone implants in rats, mainly the modifications in angiogenesis and the expression of vascular endothelial growth factor (VEGF).


METHODS
A pocket was performed on the animal's back, where the silicone implants were introduced. Two groups of animals received a polyurethane-coated silicone implant and the other groups received a textured-surface silicone implant, and the capsules around the prostheses were submitted to histologic and immunohistochemistry analysis, 30 or 90 days after surgery.


RESULTS
The capsules around the polyurethane-coated silicone prostheses were significantly thicker than the textured-surface silicone implants. Furthermore, the layer adjacent to the polyurethane-coated silicone implants was more cellular and irregular than the layer around the textured-surface silicone implants. Textured implant periprosthetic capsules presented fewer inflammatory cells and less vascularization than the polyurethane-coated silicone implants. The collagen layer of periprosthetic tissue of textured implants appears to be more continuous and aligned in parallel fashion than polyurethane-coated implants. Immunohistochemical analysis revealed high levels of transforming growth factor-β and VEGF in the capsules around the polyurethane-coated silicone implants when compared with the textured-surface silicone implants.


CONCLUSIONS
These findings suggest that the intense VEGF expression in capsules around the polyurethane-coated silicone implant is able to improve the tissue vascularization, resulting in a softer capsule compared with the textured-surface silicone implant.
Florianópolis, Santa Catarina, Brazil From Programa de Pós-Graduação em Ciências Médicas, Centro de Ciências da Saúde; Cirurgia Plástica, Hospital Universitário; and Serviço de Anatomia Patológica, Departamento de Clínica Cirúrgica, and Programa de Pós-Graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina.
Vilberto J
VJ
Vieira
Armando J
AJ
d'Acampora
Ana Beatriz W
ABW
Marcos
Gabriella
G
Di Giunta
Zulmar A A
ZAA
de Vasconcellos
Jorge
J
Bins-Ely
Rodrigo
R
d'Eça Neves
Cláudia P
CP
Figueiredo
D000199:Actins / Q000378:metabolism; D000818:Animals; D018427:Breast Implants; D020099:Coated Materials, Biocompatible; D005260:Female; D005549:Foreign-Body Reaction / Q000473:pathology / Q000517:prevention & control*; D007124:Immunoenzyme Techniques; D011140:Polyurethanes; D051381:Rats; D017208:Rats, Wistar; D020034:Silicone Gels; D013499:Surface Properties; D016212:Transforming Growth Factor beta / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D014945:Wound Healing / Q000502:physiology
D000199:Actins; D020099:Coated Materials, Biocompatible; D011140:Polyurethanes; D020034:Silicone Gels; D016212:Transforming Growth Factor beta; D042461:Vascular Endothelial Growth Factor A