There is provided a biocompatible material for delivering a biological molecule to target location, the material comprising: —；a hydrogel matrix material, —；a divalent cation-phosphate nanoparticle (in particular Calcium Phosphate), —；and a biological molecule (in particular a nucleic acid) complexed with the nanoparticle； wherein the nanoparticle is embedded within the hydrogel matrix material. The biocompatible material, particularly when in a 3D form, can be used in the treatment of various diseases. A preferred method of embedding the nanoparticles and biological molecules in the matrix is by electrophoretic transfer.
