182. Nanoscale Surface and Elemental Composition Analysis of Breast Implant Shells

PURPOSE: Breast implant surface topographies as small as 10 nm can influence fibroblast adhesion and capsular contracture, as well as bacterial adhesion and biofilm formation1,2. While previous studies have explored the microscale surface textures resulting from various implant texturing methods, such as imprinting (Mentor) and diffusion gas (Sientra), the influence of these methods on nanoscale features has been less studied. There are also concerns about the presence of heavy metals on implant surfaces and their potential role in breast implant illness. This study provides a detailed analysis of the nanoscale surface characteristics and elemental composition of four distinct breast implant surfaces with different texturing methods. METHODS: Two smooth silicone breast implants (Allergan Natrelle and Mentor MemoryGel) and two textured implants (Sientra TrueTexture and Mentor MemoryShape) were analyzed. Each sample was sputter-coated with a 5nm layer of platinum and palladium to reduce charging artifacts. High-resolution images were captured using a Zeiss Gemini 560 scanning electron microscope (SEM) at 100x and 2000x magnifications to evaluate both microscale and nanoscale topographies. Elemental analysis was performed using energy-dispersive X-ray spectroscopy (EDS) to detect trace heavy metals. RESULTS: SEM analysis revealed distinct surface topographies across the implants. The textured Sientra implant displayed an open pore microtexture, with nanoscale wrinkling visible at 2000x magnification. The textured Mentor implant exhibited large, irregular depressions with nodular outcrops and similar nanoscale wrinkling. The smooth Mentor implant showed small, rocky surface features on an otherwise smooth background. The smooth Allergan implant showed no surface features at 100x but displayed nanoscale wrinkling at higher magnification. EDS analysis identified carbon, oxygen, and silicon as the primary elements in all samples, with no significant heavy metal contamination detected. CONCLUSION: Both textured and smooth breast implants possess nanoscale surface features that may influence fibroblast adhesion and the risk of capsular contracture. While the different texturing methods used for the Sientra and Mentor implants resulted in distinct microtextures, their nanoscale wrinkling was similar. Additionally, the presence of nanoscale features on smooth implants suggests that even these surfaces may influence tissue integration, traditionally associated more with textured implants. No significant levels of heavy metals were detected, and further research is needed to explore other factors contributing to breast implant illness.