Dynamics of Active Colloid Engulfment by Giant Lipid Vesicles

Entry of particles inside cells may occur following different pathways involving biological, chemical and physical processes, leading to the engulfment of the particle by the cellular membrane. Recently, we have focused our attention on the physical mechanisms governing the interaction between driven or active colloids and giant lipid vesicles in the absence of strong binding interactions [1][2]. Using optical tweezers, we have shown that the entry of microparticles is strongly dependent on the membrane tension while the contribution of the microparticle material properties is negligible in the low tension regime [1]. We have also reported on the orbital motion of active platinum colloids around relatively tense giant lipid vesicles [2], and vesicle transportation by partially engulfed active colloids [3]. Taking advantage of these findings, we have designed active particles powered by sugar and light and study the encounter dynamics of active colloids with giant vesicles. Our experiments shed light on the physical criteria required to observe membrane shape transitions leading to active particle endocytosis in giant vesicles [4].