In the present study silver nanoparticles were synthesized and the biological distribution as well as the potential toxicity was studied. Two different concentrations of silver nanoparticles entrapped in montmorillonite were tested in Swiss mice. The animal study demonstrated that the Ag (0) -montmorillonite was nontoxic, showed no immune response, exhibited increased blood half-life, crossed BBB and increased neurotransmission. These observations indicated that Ag (0) -montmorillonite enables diverse applications in life sciences such as drug development, protein detection and gene delivery for any organs in broad, lungs and brain in particular.