A process to \"carve\" complicated shapes into nanoparticles has been unveiled by Spanish researchers who say the technique could lead to medical advances. Scientists at the Catalan Institute of Nanotechnology in Bellaterra said a chemical process that hollows out the particles into shapes such as double-walled boxes and multi-chambered tubes would aid in the creation of more complex nano-objects, the BBC reported Friday. Such nano-objects could ultimately be used to improve medical tests and aid drug treatments, they said. Particles could be \"carved\" out to absorb different energy wavelengths, leading to body scanners more accurate than current magnetic resonance imaging equipment. The technique could also aid drug delivery, researchers said. \"It\'s a wonderful molecular suitcase,\" lead researcher Victor Puntes said. \"You can have different sizes of cavity, meaning that different-sized molecules enter different rooms of a structure. \"So you can have complex and controlled relief on the nanoscale -- like cell dosing -- dosing with a mixture of drugs that would otherwise be difficult to carry out,\" he said.