Superparamagnetic Biomembranes for Dynamic Nanoparticle and Molecular Patterning

We introduce superparamagnetic biomembranes as a novel, actively tunable hybrid platform. The superparamagnetic biomembranes are supported lipid bilayers (SLBs) with defined lipid composition and site-specific coupling of proteins and superparamagnetic nanoparticles (MNPs). Application of magnetic field gradients induces rapid and fully reversible lateral transport of lipid-anchored MNPs with forces in the femtonewton range. Using single magnetic tips as well as multiple magnetic tips and line structures, we achieve parallelized and spatially defined MNP patterning. Transition of the SLB from the liquid-crystalline phase to the gel phase enables reversible immobilization of the patterned MNP distributions. Local MNP accumulation displaces lipids and membrane-associated proteins, including Neutravidin, mEGFP, and CD19, thereby generating inverse molecular gradients that are recognized by living cells. This biocompatible substrate with dynamically controllable nanoparticle and molecular organization provides a versatile framework for applications in bio- and nanotechnology.