Smart Multifunctional Hollow Microspheres for the Quick Release of Drugs in Intracellular Lysosomal Compartments

Prepared to self-destruct: When poly(d,l-lactic-co-glycolic acid) (PLGA) hollow microspheres containing NaHCO3 entered the endocytic organelles of a live cell, the NaHCO3 in the aqueous core reacted with protons that infiltrated from the compartment to generate CO2 gas. The evolution of CO2 bubbles led to the formation of small holes in the PLGA shell and thus rapid release of the encapsulated drug doxorubicin (DOX; see picture).