In Vitro Assessment of Gold Nanoparticles Synthesized by Gamma Irradiation for Antimicrobial and Anticancer Effects

The emergence of multidrug-resistant microbes presents a serious public health threat that requires new antimicrobial methods. A potential solution to combat resistance involves using metal nanoparticles that possess improved biological characteristics. The researchers have synthesized gold nanoparticles (Au-NPs) using gamma irradiation of Polyacrylamide (PAM) at 5, 10, and 15 kGy doses and through Au/chitosan nanocomposite production methods. They have also assessed the antimicrobial and anticancer functions of the produced nanomaterials by testing them on various microorganisms and cancer cell lines. Gold nanoparticles exhibited strong antibacterial effects against multiple Gram-positive bacterial strains, including <i>Bacillus subtilis</i>, <i>Micrococcus luteus</i>, <i>Staphylococcus epidermidis</i>, <i>Staphylococcus aureus</i>, <i>and Streptococcus mutans</i>, as well as methicillin-resistant <i>Staphylococcus aureus</i> (MRSA). <i>Escherichia coli</i> showed a significant inhibition zone of 23 mm, and <i>Salmonella</i> spp. showed similar inhibition. The inhibition zone for <i>Klebsiella pneumoniae</i> ATCC 13883 revealed resistance. The Au-NPs/chitosan composite showed moderate antifungal effectiveness against <i>Syncephalis racemosum</i> and <i>Aspergillus niger</i> alongside <i>Candida albicans</i> and several other tested fungi. Au-NPs showed cytotoxicity to breast MCF-7 cells, as well as liver HepG-2 cells and colon HCT-116 cells. The combination of Au-NPs with chitosan demonstrated limited effectiveness in countering hepatitis A virus (HAV-10) and herpes simplex virus type 1 (HSV-1). The combination of gamma-irradiated Au-NPs with biopolymers like chitosan demonstrates significant promise in antimicrobial and anticancer biomedical applications.