Green Synthesis of Colloidal Metallic Nanoparticles Using Polyelectrolytes for Biomedical Applications

Metallic nanoparticles have found applications in numerous fields, such as biosensors, antimicrobial agents, theragnostic, cancer hyperthermia, gene and drug delivery platforms, and bactericide. However, the development of these and other applications is still limited by the methods of synthesis of nanoparticles which usually use toxic substance as reducing and stabilizing agents. Because of this, there is an increasing interest in the development of methods of green synthesis. In this chapter there is a review to green synthesis of metallic nanoparticles using polyelectrolytes that act as a reducing and stabilizer agents, without toxic substances. The use of colloidal poses an easy way of administration and manipulation for metallic nanoparticles in living organisms. Colloidal nanoparticles of gold have been studied as vectors in the administration of pharmaceuticals for the treatment of tumors, as immunosensor or as DNA sequence colorimetric detector. There are reports about the synthesis and stabilization of metallic nanoparticles in colloidal solution using polyelectrolytes. Recent research has been focused on the design of new anionic polyelectrolytes and macroelectrolytes with reducing agent properties for the synthesis and stabilization of colloidal metallic nanoparticles. The use of polyelectrolytes as reducing and stabilizing agents is a viable alternative in green chemistry to avoid the use of toxic substances during synthesis. The choice of natural or bio-based polyelectrolytes like proteins and polysaccharides or their derivatives allows for the obtaining of stabilized nanoparticles with molecules that confer them biocompatibility and that facilitate their function of biological reconnaissance.