Controllable switch of dissolution kinetics mechanism in drug microcapsules

Controllable continuous release of functional materials from capsules is one of the unmet functions of theragnosis particles; on this way, understanding cargo-fluid interactions in vitro is an essential milestone. We develop a flexible platform to investigate single particle-fluid interactions utilizing a glass micropipette as a highly localized flow source around an optically trapped particle. In proof-of-concept experiments this microparticle is sensitive to local microflows distribution, thus serving as a probe. The very same flows are capable of the particle rotating (i.e., vaterite drug cargo) at frequencies dependent on the mutual particle-pipette position. The platform flexibility comes from different interactions of a tweezer (optical forces) and a pipette (mechanical/hydrodynamical) with micro-particle, which makes this arrangement an ideal micro-tool. We studied the vaterite dissolution kinetics and demonstrated it can be controlled on demand, providing a wide cargo release dynamic rate. Our results promote using inorganic mesoporous nanoparticles as a nanomedicine platform.