Theory 12/Nanoscale/Nanoparticle uptake
Uptake Is Size Against Membrane
The claim
Cellular uptake of nanoparticles is set by the ratio of particle diameter to membrane thickness, with an optimum where the particle can be wrapped without being excluded.
01Mechanism
Endocytosis requires the membrane to deform around the particle; too small and there is no driving force, too large and wrapping costs too much area.
02Prediction
Uptake should peak at an intermediate ratio.
03Refutation
Uptake increasing monotonically with size would remove the wrapping cost.