Background: Several studies have reported adverse immunological effects of silicone due to their ability to induce proinflammatory molecules, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). In recent years, use of nanoparticles has been under fast development for therapeutic drug targeting, diagnostic imaging, and immune response in various fields of nanomedicine. The authors hypothesize that immune responses induced by in vivo use of silicone materials can be reduced or eliminated by the use of nanosilicone.
Methods: Peripheral blood mononuclear cells obtained from naïve normal subjects were cultured with different concentrations of silicone nanoparticles and microparticles for 24 hours. The culture supernatants were quantitated for TNF-α, IL-6, and interferon-γ (IFN-γ) secretion by enzyme-linked immunosorbent assay. The pellets were used for specific IL-6, TNF-α, and IFN-γ gene expression by real-time polymerase chain reaction, respectively. Cytotoxicity was evaluated by XTT viability assay. Results were compared between silicone nanoparticles and microparticles and untreated controls.
Results: Silicone nanoparticles up to 100 μg/ml did not induce any detectable levels of specific TNF-α, IFN-γ, and IL-6 gene expression and protein production and the results were comparable to those for untreated controls. Silicone microparticles at 100 μg/ml, however, significantly induced the production and gene expression of TNF-α, IL-6, and IFN-γ by peripheral blood mononuclear cells. XTT viability assay showed that silicone nanoparticles or microparticles, even at the highest concentration used, were not cytotoxic to cells.
Conclusions: The results suggest that silicone nanoparticles can be engineered to avoid immune recognition and subsequent silicone microparticle-related adverse effects and thus may be of therapeutic significance in the cosmetic industry, plastic surgery, and aesthetic medicine.