title: Enhanced Antimicrobial and Anticancer Activity of Silver and Gold Nanoparticles Synthesised Using Sargassum incisifolium Aqueous Extracts.
abstract: A detailed, methodical approach was used to synthesise silver and gold nanoparticles using two differently prepared aqueous extracts of the brown algaeSargassum incisifolium. The efficiency of the extracts in producing nanoparticles were compared to commercially available brown algal fucoidans, a major constituent of brown algal aqueous extracts. The nanoparticles were characterised using TEM, XRD and UV/Vis spectroscopy and zeta potential measurements. The rate of nanoparticle formation was assessed using UV/Vis spectroscopy and related to the size, shape and morphology of the nanoparticles as revealed by TEM. The antioxidant, reducing power and total polyphenolic contents of the aqueous extracts and fucoidans were determined, revealing that the aqueous extracts with the highest contents produced smaller, spherical, more monodisperse nanoparticles at a faster rate. The nanoparticles were assessed against two gram-negative bacteria, two gram-positive bacteria and one yeast strain. In contrast to the literature, the silver nanoparticles produced using the aqueous extracts were particularly toxic to Gram-negative bacteria, while the gold nanoparticles lacked activity. The cytotoxic activity of the nanoparticles was also evaluated against cancerous (HT-29, MCF-7) and non-cancerous (MCF-12a) cell lines. The silver nanoparticles displayed selectivity, since the MCF-12a cell line was found to be resistant to the nanoparticles, while the cancerous HT-29 cell line was found to be sensitive (10% viability). The gold nanoparticles displayed negligible toxicity.
authors.affiliation: School of Pharmacy, University of the Western Cape, Bellville 7535, South Africa. mcozeemm@gmail.com.|Department of Biotechnology, University of the Western Cape, Bellville 7535, South Africa. mcozeemm@gmail.com.
authors.forename: Mokone
authors.initials: M
authors.lastname: Mmola
authors.affiliation: Biocatalysis and Technical Biology Research Group, Institute of Biomedical and Microbial Biotechnology, Cape Peninsula University of Technology, Bellville 7535, South Africa. LeRoesM@cput.ac.za.
authors.forename: Marilize Le
authors.initials: ML
authors.lastname: Roes-Hill
authors.affiliation: Biocatalysis and Technical Biology Research Group, Institute of Biomedical and Microbial Biotechnology, Cape Peninsula University of Technology, Bellville 7535, South Africa. DurrellKa@gmail.com.
authors.forename: Kim
authors.initials: K
authors.lastname: Durrell
authors.affiliation: Department of Biological Sciences, University of Cape Town, Rondebosch 7701, South Africa. john.bolton@uct.ac.za.
authors.forename: John J
authors.initials: JJ
authors.lastname: Bolton
authors.affiliation: Department of Biotechnology, University of the Western Cape, Bellville 7535, South Africa. nsibuyi@uwc.ac.za.
authors.forename: Nicole
authors.initials: N
authors.lastname: Sibuyi
authors.affiliation: Department of Biotechnology, University of the Western Cape, Bellville 7535, South Africa. memeyer@uwc.ac.za.
authors.forename: Mervin E
authors.initials: ME
authors.lastname: Meyer
authors.affiliation: School of Pharmacy, University of the Western Cape, Bellville 7535, South Africa. dbeukes@uwc.ac.za.
authors.forename: Denzil R
authors.initials: DR
authors.lastname: Beukes
authors.affiliation: Department of Chemistry, University of the Western Cape, Bellville 7535, South Africa. Ebeukes@uwc.ac.za.
authors.forename: Edith
authors.initials: E
authors.lastname: Antunes
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects; D045744:Cell Line, Tumor; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects; D013293:Enterococcus faecalis / Q000187:drug effects; D006046:Gold / Q000494:pharmacology*; D055772:Green Chemistry Technology; D019073:HT29 Cells; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects; D061986:MCF-7 Cells; D053768:Metal Nanoparticles / Q000627:therapeutic use*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D010936:Plant Extracts / Q000494:pharmacology*; D044647:Sargassum / Q000737:chemistry*; D012834:Silver / Q000494:pharmacology*; D013052:Spectrometry, X-Ray Emission
chemical_list: D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D010936:Plant Extracts; D012834:Silver; D006046:Gold
keywords: Sargassum incisifolium; antibacterial activity; cytotoxicity; fucoidans; gold nanoparticles; green synthesis; silver nanoparticles; total phenolic content