The present invention relates to nanofibers (1) comprising an outer membrane (2) and a core (3) wherein said outer membrane (2) is made of fibroin and said core (3) is a biocompatible and biodegradable polymer. The present invention further relates to a method for obtaining said nanofibers and the use thereof to convey bioactive molecules and/or particles and/or cells and/or in the treatment of diseases. The present invention also relates to said powdered nanofibers, optionally suspended in an aqueous solution, and to a hydrogel system comprising said powdered nanofibers and to the use of said powdered nanofibers and of said system to convey bioactive molecules and/or particles and/or cells and/or in the treatment of diseases.
