Figure 4. Anti-bacterial function of the AgNP biliary stent in vitro.
(a) The colony number of E. coli was significantly decreased after 1 hour of co-culture of AgNPs and E. coli versus the control. (b) The survival ratios of E. coli were compared at different time points of AgNPs and E. coli co-culture versus the control. AgNPs-1M: AgNPs biliary stent storage for 1 month. (c) The colony number of Staph. aureus was compared in AgNPs and E. coli co-culture versus the control. Magnification: 400×. (d) The colony number of Enterococcus was compared in AgNPs and E. coli co-culture versus the control. Magnification: 400×. (e) The colony number of P. aeruginosa was compared in AgNPs and E. coli co-culture versus the control. Magnification: 400×. IOD: integral optical density; HPF: high-power fields. The bacterial number was determined with the spread plate method.