Antimicrobial activity and controlled release of nanosilvers in bacterial cellulose composites films incorporated with montmorillonites

作者：Li Yi Tsen; Lin Shih Bin; Chen Li; Chen Hui Huang^*

来源：Cellulose, 2017, 24(11): 4871-4883.

DOI：10.1007/s10570-017-1487-3

• Bacterial cellulose
• Montmorillonite
• Silver nanoparticles
• Antimicrobial activity
• Controlled release

Silver nanoparticles (AgNPs) were synthesized by NaBH4 reduction and loaded in the dry-fabricated biofilm (DFBF) or the interlayer space of montmorillonite (MMT), generating AgNPs/DFBF or AgNPs/MMT composites, respectively. Use of NaBH4 at lower concentrations resulted in smaller the derived AgNPs, which exhibited superior antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Transmission electron microscopy images revealed conformation of AgNPs in DFBF and MMT with sizes of 20-160 and 2 nm, respectively. The results suggested that AgNPs were immobilized more firmly in MMT than in DFBF, which prevented the flocculation of AgNPs. The adsorption of AgNPs/MMT composites on DFBF resulted in the formation of AgNPs/MMT/DFBF composites, which further inhibited AgNPs migration. Furthermore, the silver release ratios of the AgNPs/DFBF, AgNPs/MMT, and AgNPs/MMT/DFBF composites were 6.7, 1.05, and 0.414% within 48 h, respectively. The minimum inhibitory concentration of silver in the medium for the AgNPs/MMT/DFBF composite against S. aureus was as low as 0.30 mu g/mL; thus, AgNPs/MMT/DFBF composite films are suitable candidates for applications in sustained-release antimicrobial dressings.

• 出版日期2017-11