Core-template-free strategy for preparing hollow nanospheres

A core-template-free strategy for preparing biocompatible and biodegradable hollow polymeric nanospheres is described. The hollow nanospheres are formed in a completely aqueous system without the aid of surfactants, precursors of copolymers, template cores and emulsion phases, typically used for making hollow nanospheres and thus decreases their potential toxicity. The approach can be performed at a relatively high concentration of 0.5-20 g L-1, and on a large scale. The approach also provides a functional surface with chemical groups for subsequent chemical reactions at the surface.