The surface stress of biomedical silicones is a stimulant of cellular response
Silicones are commonly used in the field of medicine to lubricate syringes, encapsulate medical devices, and develop surgical implants. Although the material is generally viewed as relatively inert to cells, they can trigger a variety of inflammatory responses and other deleterious effects—but the mechanisms underlying their bioactivity remain to be determined. In a new report, Zhu Cheng, and a research team in chemical and biomedical engineering at Cornell and Stanford University, U.S., detailed that silicone liquids and gels have high surface stresses to strongly resist deformation at cellular strengths. For instance, biomedical silicones used for syringe lubricants from FDA-approved breast implants can readily adsorb matrix proteins to activate canonical rigidity sensing pathways through their surface stresses. Using 3-D cell culture models, the bioengineers showed how liquid silicone droplets supported robust cellular adhesion to form multinucleated, monocyte-derived cell masses recapitulating characteristics of granuloma formation similar to those observed during a foreign...