Fig. 4
a Concentration–absorption curve of GA-Ag NP solution. b Change in nanosilver concentration due to DT soaking in GA-Ag NP solution. c Residual amounts of Ag NPs on the tendons of the nongrafted ([EDC] = [NHS] = 0; DT) and grafted ([EDC] = [2NHS] = 40 mM, DT-Ag) groups after different numbers of ultrasonication cycles, where “a” is the relative GA-Ag NP grafting amount, “b” is the total amount of GA-Ag NPs, and χattachment can be calculated by a/b × 100%. d Left: TEM image showing fibers and GA-Ag NPs in the grafted group after ultrasonication; right: TEM image showing GA-Ag NPs scattered in the solution. e Continuous release of GA-Ag NPs in nongrafted and grafted groups assessed using a shaking table. f Continuous release of GA-Ag NPs in the two groups assessed after different times of ultrasonic cleaning. g, h Results of inhibition zone tests obtained for DT and DT-Ag thin slices and related statistical analysis. i Activities of DT and DT-Ag against planktonic bacteria. j SEM images of DT and DT-Ag after incubation with bacteria