BREAST SURGERY Textured and Smooth Breast Implants: Is There a Difference in the Chemical Structure of Silicone? An Analysis With Fourier Transformation Infrared and Attenuated Total Reflectance Spectroscopy Paolo Persichetti, MD, PhD,* Stefania Tenna, MD, PhD,* Sergio Delfino, MD, PhD,* Franca Abbruzzese, PhD,† Marcella Trombetta, PhD,† and Nicolo ` Scuderi, MD‡ Abstract: Scientific controversy concerning silicone and its biocompatibility has been ongoing for the last 10 years. This study on textured and smooth silicone breast implant shells using fourier transformation infrared spectros- copy associated with attenuated total reflectance cells aimed to identify eventual chemical modifications of silicone induced by texturization. The surfaces of 8 new implants produced by 2 well-known manufactures have been taken into consideration. A sample 1 cm 2 has been harvested from the anterior and posterior sides of textured and smooth shells. Infrared spectra were then recorded, evaluated, and compared with the reference spectrum of pure silicone. Potentially reactive groups, known as silanols, were identified, in all shells, intensity increasing in textured implants (P  0.05), whereas no silanols were detected in the spectrum of pure silicone. These results suggest that polar groups, present in manipulated silicone might influence capsula formation. Key Words: breast implants, textured implants, smooth implants, silicone, FTIR/ATR spectroscopy (Ann Plast Surg 2009;63: 373–377) T he introduction of silicone breast implants, by Cronin early in the 60s, marked the beginning of a new era in plastic surgery, which rapidly spread stimulating technological and scientific updates. Over the last 30 years, surgeons, scientists, and producers have worked to better understand the interaction between silicone and the human body, to improve the quality and duration of the prosthesis. 1–4 Surfaces textured ad hoc were prepared, aimed at reducing capsular contracture by way of breakdown of forces, albeit there is little evidence showing whether this effect is maintained in the long- term. 5 Capsular contracture is currently widely studied, using vari- ous methods, including histochemistry, scansion electronic microscopy, energy-dispersive x-ray microanalysis, and infrared microspectroscopy, however, these studies have all focused primarily on the peripros- thetic tissue rather than on the role of the implant surface in capsula formation. 6 –10 Since the 40s, on account of Rowes’ experiment, on animals, silicone, polydimethylsiloxane (PDMS), has been considered an inert biomaterial, far better tolerated by the mammalian body than other synthetic polymers. 11 Indeed, several generations of implants have been produced using PDMS as the basic material. However, more recent theories suggest that silicone is not as inert as previ- ously held especially after mechanical manipulation that might include the superficial trauma induced by the manufacturing process as well as the compressive stress produced during insertion. 12–16 The texturization process has been scrupulously investigated by scansion electronic microscopy studies, which have confirmed that no consistent damage occurs to the physical structure of silicone shell implants, regardless of the method used such as imprint foam or Siltex (Mentor Co, Santa Barbara, CA), and the lost-salt tech- nique, Biocell shell, introduced by Inamed Co (Allergan Inc, Irvine, CA). 7 However, due to variability in the polymeric reaction, the elastomer used, in the various types of implants, showed vastly different properties. 17 To the best of our knowledge, no articles focusing on the analysis and classification of the reactive sites exposed on silicone have, as yet, been published. 18 –20 Traditional and vibrational infrared (IR) spectroscopy are 2 methods commonly employed to define the superficial chemical structure of biomaterials and their composition, providing a multi- tude of information on specific functional groups/moieties and their spatial location. 8 Over the last 10 years, Fourier transformation IR spectroscopy associated with attenuated total reflectance cells (FTIR/ATR), has been specifically used to estimate the degree of molecular connectivity in silicon oxide. This technique is both useful and precise allows polymer surface analysis without having to employ solvents, or resins, which could impair correct identification of the chemical bonds exposed. 21–27 Thanks to the low energy of IR rays, in fact, chemical bonds, even in thin layers, can be studied, without damaging moieties and providing specific spectra that characterize the surface of the solid, like a fingerprint. 9 Aim of the present study was to evaluate textured and smooth silicone breast implant shells using FTIR/ATR spectroscopy, in the attempt to identify eventual chemical modifications in silicone induced by texturization. MATERIALS AND METHODS For this limited study, 2 well-known manufacturers (Inamed Co, Allergan Inc, and Mentor Co) following informed consent, offered a total of 8 silicone gel-filled round breast implants. Each company, contributed with 2 textured and 2 smooth implants, comparable in size. All implants were new and packed. The pros- theses were catalogued and classified as outlined in Table 1. A sample of 1 cm 2 of each shell was randomly removed, by scissors, from the anterior area of the shell implant. A second identical section was collected from the posterior area (as a control sample) to check shell homogeneity. FTIR/ATR spectroscopy was used to observe the chemical structure of each sample. IR spectra were recorded with the Nicolet Received January 10, 2008, and accepted for publication, after revision, Novem- ber 14, 2008. From the *Plastic Surgery Unit, Campus Bio-Medico University, Rome, Italy; †Laboratory of Chemistry and Biomaterials, Campus Bio-Medico University, Rome, Italy; and ‡Department of Plastic Surgery, La Sapienza University, Rome, Italy. Reprints: Stefania Tenna, MD, PhD, Cattedra di Chirurgia Plastica, Universita ` Campus Bio-Medico, via Alvaro del Portillo 21, 00128 Rome, Italy. E-mail: s.tenna@unicampus.it. Copyright © 2009 by Lippincott Williams & Wilkins ISSN: 0148-7043/09/6304-0373 DOI: 10.1097/SAP.0b013e3181953791 Annals of Plastic Surgery • Volume 63, Number 4, October 2009 www.annalsplasticsurgery.com | 373