The present invention relates to a method for in situ preparation of cyano-bridged coordination polymers as metal nanoparticles within a biocompatible reverse micellar system by mixing at least two reverse micellar systems, each one containing at least one metal salt precursor. The invention also relates to the stabilization of theses nanoparticles by using a biocompatible reverse micellar system. This system takes part of the synthesis as a nanoreactor which comprises at least an acylglycerol, a sterol, lecithin, ethanol and water for the preparation of stable cyano-bridged metal nanoparticles without any use of additional stabilizer agent.
