title: Enhanced stability and antibacterial efficacy of a traditional Chinese medicine-mediated silver nanoparticle delivery system.
abstract: Silver nanoparticles (AgNPs) are widely used as antibacterial products in various fields. Recent studies have suggested that AgNPs need an appropriate stabilizer to improve their stability. Some antibacterial traditional Chinese medicines (TCMs) contain various reductive components, which can not only stabilize AgNPs but also enhance their antimicrobial activity. In this study, we developed a series of novel AgNPs using a TCM extract as a stabilizer, reducing agent, and antimicrobial agent (TCM-AgNPs). A storage stability investigation of the TCM-AgNPs suggested a significant improvement when compared with bare AgNPs. Further, conjugation of TCMs onto the AgNP surface resulted in stronger antimicrobial potency on antibacterial evaluation using Pseudomonas aeruginosa, Staphylococcus epidermidis, and Staphylococcus aureus with minimum inhibitory concentration 50% (MIC50) ratios (and minimum bactericidal concentration 90% [MBC90] ratios) of AgNPs to respective TCM-AgNPs as assessment indices. Among these, P. cuspidatum Sieb. et-conjugated AgNPs (P.C.-AgNPs) had the advantage of a combination of TCMs and AgNPs and was studied in detail with regard to its synthesis and characterization. The extraction time, reaction temperature, and concentrations of AgNO3 and Polygonum cuspidatum Sieb. et extract were critical factors in the preparation of P.C.-AgNPs. Further, the results of X-ray diffraction and Fourier transform infrared spectroscopy indicated successful preparation of P.C.-AgNPs. In representative studies, P.C.-AgNPs showed a well-defined spherical shape, a homogeneous small particle size (36.78 nm), a narrow polydispersity index (0.105), and a highly negative zeta potential (-23.6 mV) on transmission electron microscopy and dynamic light scattering. These results indicate that TCM-AgNPs have a potential role as antibacterial agents in the clinic setting.
authors.affiliation: Key Laboratory of New Drug Delivery System of Chinese Materia Medica, Jiangsu Provincial Academy of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China ; Department of Pharmaceutics, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Sun
authors.affiliation: Key Laboratory of New Drug Delivery System of Chinese Materia Medica, Jiangsu Provincial Academy of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China.
authors.forename: Ding
authors.initials: D
authors.lastname: Qu
authors.affiliation: Key Laboratory of New Drug Delivery System of Chinese Materia Medica, Jiangsu Provincial Academy of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China.
authors.forename: Yihua
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Key Laboratory of New Drug Delivery System of Chinese Materia Medica, Jiangsu Provincial Academy of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China ; Department of Pharmaceutics, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Key Laboratory of New Drug Delivery System of Chinese Materia Medica, Jiangsu Provincial Academy of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China.
authors.forename: Congyan
authors.initials: C
authors.lastname: Liu
authors.affiliation: Key Laboratory of New Drug Delivery System of Chinese Materia Medica, Jiangsu Provincial Academy of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D016503:Drug Delivery Systems; D004355:Drug Stability; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D008516:Medicine, Chinese Traditional; D053768:Metal Nanoparticles / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D012834:Silver / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D004365:Drugs, Chinese Herbal; D012834:Silver
keywords: Polygonum cuspidatum Sieb. et; antibacterial; extract; silver nanoparticles; stability; traditional Chinese medicine