Co-electrospinning of core-shell polymer nanofibers (see Figure) is introduced. This process can be used for manufacturing of coaxial nanofibers made of pairs of different materials. Non-spinnable materials can be forced into 1D arrangements by co-electrospinning using a spinnable shell polymer. The method results in a novel two-stage approach for fabrication of nanotubes instead of the previously used three-stage process.