Self-Propelled Collagenase-Powered Nano/Micromotors

Nano/micromotors are active matter that can self-propel and thereby outperform Brownian motion. Pioneering motors that could only move in low-viscosity, liquid environments have been outranked by more powerful examples that are able to navigate complex environments such as biological fluids, gels, or cellulose. Herein, we assemble different collagenase-powered motors devoting special attention to parameters such as the material of the core particle and its size and morphology. We assess the characteristics of their locomotion depending on the density of the fiber networks and geometrical constraints. 500 nm polystyrene core particles in diameter exhibit top velocities of up to ∼30 μm s–1, which decrease 2–3× with increasing core size, fiber density, or when changing to silica-based cores. Taken together, this effort explores the dynamics of motors within interconnected collagen networks, toward more realistic and complex scenarios where locomotion is envisioned to be beneficial.