The pathophysiology of breast implant-related adverse outcomes, such as capsular contracture and breast implant-associated anaplastic large cell lymphoma, remains poorly understood. Herein, we explore the direct and indirect effects of smooth and textured implant shells on the viability of cell lines found within the peri-breast implant environment in vitro. The outer silicone shells of Allergan and Mentor breast implants were de-gelled and cut to exactly line the walls of 96-well cell culture plates. Endothelial, fibroblast, and triple negative breast cancer cell lines were cultured in the presence and absence of implant shells over 8 days. To examine indirect effects, fresh media incubated with implant shells were collected and separately cultured with the same cell lines. These media were further diluted with fresh media and given to cells to examine a "dose dependent" response. Additionally, the effect of pre-soaking implant shells in fresh media prior to cell culture was investigated. Serum free media incubated with implant shells were interrogated for presence of nanoparticles. Cell counts at each culture condition were assessed over 8 days. The presence of implant shells consistently demonstrated a negative effect on cell count that persisted across cell lines and experimental conditions, with a greater effect observed from textured surface shells over smooth. Implant fill silicone gel alone did not influence cell count. Implant-conditioned media (CM) similarly exerted a negative effect, even without direct cell exposure to an implant shell. Dilution of the CM attenuated this effect. Pre-soaking implants in high serum media also reduced the negative effect when incubated with cells, suggesting the role of serum protein adsorption. Nanometer-range sized particles were detected in serum-free media incubated with all implants, with a higher concentration released from textured samples. These studies suggest breast implant shells may negatively impact cell viability through several different mechanisms and uncover valuable insights into the cellular interactions and potential effects of these widely used prostheses on their immediate environment.