Controlled production of alginate nanocomposites with incorporated silver nanoparticles aimed for biomedical applications

The production of nanocomposite alginate microbeads with electrochemically synthesized silver nanoparticles (AgNPs) based on the electrostatic extrusion technique was investigated with respect to their potentials for utilization in pharmaceutical, and biomedical applications. It was shown that electrochemical synthesis of AgNPs results in the reduction of practically all the Ag+ present in the initial solution, yielding stable Ag/alginate colloid solutions that were demonstrated to be suitable for sterilization, manipulation, and electrostatic extrusion with retention of the AgNPs. The presence of AgNPs in the alginate colloid solutions had negligible effects on the size of the produced Ag/alginate microbeads, which was mainly determined by the electrostatic potential applied during the extrusion. On the other hand, the incorporation of AgNPs within the alginate hydrogel induced slight changes in biomechanical properties of the microbeads determined in a biomimetic bioreactor. Thus, packed beds of nanocomposite Ag/alginate microbeads exhibited a slightly higher dynamic compression modulus as compared to that of control alginate microbeads (154 +/- 4 and 141 +/- 2 kPa, respectively). On the other hand, the equilibrium unconfined compression modulus was significantly lower for the nanocomposite microbeads as compared to that of the controls (34 +/- 2 and 47 +/- 1 k.Pa, respectively).