Polysilicon Microchips Functionalized with Bipyridinium-Based Cyclophanes for a Highly Efficient Cytotoxicity in Cancerous Cells.

The use of micrometric-sized vehicles could greatly improve selectivity of cytotoxic compounds as their lack of self-diffusion could maximize their retention in tissues. We have used polysilicon microparticles (SiµP) to conjugate bipyridinium-based compounds, able to induce cytotoxicity under regular intracellular conditions. Homogeneous functionalization in suspension was achieved, where the open-chain structure exhibits a more dense packing than cyclic analogues. The microparticles internalized induce high cytotoxicity per particle in cancerous HeLa cells, and the less densely packed functionalization using cyclophanes promotes higher cytotoxicity per bipy than with open-chain analogues. The self-renewing ability of the particles and their proximity to cell membranes may account for increased lipid peroxidation, achieving toxicity at much lower concentrations than that in solution and in less time, inducing highly efficient cytotoxicity in cancerous cells.