title: Antibacterial activity and increased freeze-drying stability of sialyllactose-reduced silver nanoparticles using sucrose and trehalose.
abstract: The resistance to current antibiotics results in the emergence of health-threatening bacteria. Silver nanoparticles are known to exhibit broad-spectrum antibacterial activities without the development of resistance. Herein, we developed a green synthetic method for the preparation of silver nanoparticles with sialyllactose instead of toxic chemicals as a reducing agent, which would improve its therapeutic applicability and increase its biocompatibility. Oven incubation, autoclaving and microwave irradiation methods were applied to prepare the silver nanoparticles. High resolution-transmission electron microscopy and atomic force microscopy images revealed mostly spherical and amorphous silver nanoparticles with an average diameter of 23.64 nm. Fourier Transform-infrared spectra suggest that the N-H amide of sialyllactose might be involved in the binding of silver nanoparticles. Based on thermogravimetric analyses, 2,3-sialyllactose-reduced silver nanoparticles are composed of 54.3 wt% organic components and 45.7 wt% metallic silver. Enhanced antibacterial activities of silver nanoparticles (approximately 8-fold) were observed against Pseudomonas aeruginosa, Escherichia coli and Salmonella typhimurium (minimum inhibitory concentration 16 microg/mL). Next, we employed the use of carbohydrate stabilizers to increase the stability of silver nanoparticles during a freeze-drying process. It was found that sucrose and trehalose were the most effective stabilizers. In addition, silver nanoparticles possessed excellent salt stability as well as on-the-shelf stability in the presence of these stabilizers. Derivatives of sialic acid are known to be anti-influenza agents; therefore, the newly prepared silver nanoparticles may serve as useful antibacterial and antiviral agents to cope with both pathogenic bacteria and viruses in the near future.
authors.affiliation: College of Pharmacy, Inje University, 607 Obang-dong, Gimhae, Gyeongnam 621-749, Republic of Korea.
authors.forename: Hwa Jung
authors.initials: HJ
authors.lastname: Noh
authors.forename: A-Rang
authors.initials: AR
authors.lastname: Im
authors.forename: Hyun-Seok
authors.initials: HS
authors.lastname: Kim
authors.forename: Jae Kyung
authors.initials: JK
authors.lastname: Sohng
authors.forename: Chong-Kook
authors.initials: CK
authors.lastname: Kim
authors.forename: Yeong Shik
authors.initials: YS
authors.lastname: Kim
authors.forename: Seonho
authors.initials: S
authors.lastname: Cho
authors.forename: Youmie
authors.initials: Y
authors.lastname: Park
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000494:pharmacology*; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology; D002240:Carbohydrate Sequence; D004355:Drug Stability; D004926:Escherichia coli / Q000187:drug effects; D005079:Excipients / Q000737:chemistry; D005612:Freeze Drying / Q000379:methods; D007785:Lactose / Q000031:analogs & derivatives* / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D008969:Molecular Sequence Data; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012486:Salmonella typhimurium / Q000187:drug effects; D012794:Sialic Acids / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013395:Sucrose / Q000737:chemistry*; D014199:Trehalose / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D001672:Biocompatible Materials; D005079:Excipients; D012794:Sialic Acids; D012834:Silver; D013395:Sucrose; D014199:Trehalose; D007785:Lactose