A one-step pathway hasbeen adopted to fabricate biodegradable polylactide (PLA) hollow spheresby interfacial polymerization in an oil-in-water emulsion system. The mechanism of sphere formation is

suggested with respect to interfacial cross-linking polymerization and subsequent precipitation of the unreacted PLA macromonomers onto the preformed shells. Their hollow nature and morphology were verified by transmission electron microscopy and scanning electron microscope characterizations.