Cell signaling is initiated by characteristic protein patterns in the plasma membrane, but tools to decipher their molecular organization and activation are hitherto lacking. Among the well‐known signaling pattern is the death inducing signaling complex with a predicted hexagonal receptor architecture. To probe this architecture, DNA origami‐based nanoagents with nanometer precise arrangements of the death receptor ligand FasL are introduced and presented to cells. Mimicking different receptor geometries, these nanoagents act as signaling platforms inducing fastest time‐to‐death kinetics for hexagonal FasL arrangements with 10 nm inter‐molecular spacing. Compared to naturally occurring soluble FasL, this trigger is faster and 100× more efficient. Nanoagents with different spacing, lower FasL number or higher coupling flexibility impede signaling. The results present DNA origami as versatile signaling scaffolds exhibiting unprecedented control over molecular number and geometry. They define molecular benchmarks in apoptosis signal initiation and constitute a new strategy to drive particular cell responses.

Remote control of cellular functions is a key challenge in biomedical research. Only a few tools are currently capable of manipulating cellular events at distance, at spatial and temporal scales matching their naturally active range. A promising approach, often referred to as ‘magnetogenetics’, is based on the use of magnetic fields, in conjunction with targeted biofunctional magnetic nanoparticles. By triggering molecular stimuli via mechanical, thermal or biochemical perturbations, magnetic actuation constitutes a highly versatile tool with numerous applications in fundamental research as well as exciting prospects in nano- and regenerative medicine. Here, we highlight recent studies, comment on the advancement of magnetic manipulation, and discuss remaining challenges.

Stochastic displacements or fluctuations of biological membranes are increasingly recognized as an important aspect of many physiological processes, but hitherto their precise quantification in living cells was limited due to a lack of tools to accurately record them. Here we introduce a novel technique—dynamic optical displacement spectroscopy (DODS), to measure stochastic displacements of membranes with unprecedented combined spatiotemporal resolution of 20 nm and 10 μs. The technique was validated by measuring bending fluctuations of model membranes. DODS was then used to explore the fluctuations in human red blood cells, which showed an ATP-induced enhancement of non-Gaussian behaviour. Plasma membrane fluctuations of human macrophages were quantified to this accuracy for the first time. Stimulation with a cytokine enhanced non-Gaussian contributions to these fluctuations. Simplicity of implementation, and high accuracy make DODS a promising tool for comprehensive understanding of stochastic membrane processes.