Thesis (Ph.D.)--Chulalongkorn University, 2012

Silver nanoparticles capped with a different stabilizing agent including Folic acid(FA), Poly(4-styrenesulfonic acid-co-maleic acid) sodium salt (PSSMA), Alginic acid (AL) were prepared. Concentration of stabilizing agent was varied from 0.1 to 5 mM. These silver nanoparticles solutions were characterized by UV-Vis spectroscopy and showed the LSPR around 400 nm. Then SNP was formed layer by layer with PDADMAC via polyelectrolyte multilayers technique on glass slide and polyamide suture material. It was found that in low capping agent of SNP was formed more close packing than high capping agent. Then both coated glass slide and suture material were studied the pattern of silver ion leaching from polyelectrolyte multilayer thin film in phosphate buffer (pH 7.4) and acetic-acetate buffer (pH 5.5). The result of this study was shown that the silver ion could release from thin film in pH 5.5 more than pH 7.4 and in low capping agent had trend to release silver ion more than high capping agent. Finally, SNP solution was characterized their anticancer and antibacterial activity via MTT assay and standard method of antibacterial test(ASTME2149-10) sequentially. All condition of SNP was exposed to MCF-7, BT474, ChaGo and Jurkat cell which was a various type of cancer cell and analyzed in IC50, it was performed that SNP-AL and SNP-PSSMA were not toxic and destroy cancer cell. However, SNP-FA could kill cancer cell when increasing concentration of folic acid. It was different to Jurkat cell that all condition of SNP were more toxic than other cell. All conditions of SNP could not toxic to WI-38 cell, so this SNP was not toxic to healthy cell. For their antibacterial activity, all condition of SNP could reduce E. coli nearly 100%. However, SNP with all capping agent could reduce S. aureus less than E. coli depend on the concentration and type of capping agent.