Dose, size,
and MexAB-OprM dependent inhibitory effects of antibiotic
nanocarriers (AgMUNH-Oflx NPs) against (A) WT and (B) ΔABM cells.
Plots of normalized OD600 nm of cells cultured for 17 h
in the modified LB medium containing (a–c) AgMUNH2 NPs (absence of Oflx, control), (d) Oflx alone, and (e–g)
Oflx conjugated with the (e) 2.4 ± 0.7, (f) 13.0 ± 3.1,
and (g) 92.6 ± 4.4 nm Ag NPs, respectively. The concentration
of AgMUNH2 NPs in (a–c) of (A) and (B) contain the
same concentration of NPs as the nanocarriers with the highest Oflx
concentrations in (e–g) for each type of NP in (A) and (B)
but without carrying Oflx (control experiments for the study of effects
of NPs). The points are experimental data, and a solid line was generated
by fitting the experimental data with the equation y = a·e–bx as followings: (A): (d) y = 1.12·e–1.18x, R2 = 0.923; (e) y = 1.07·e–0.764x, R2 = 0.967; (f) y =
1.04·e–1.82x, R2 = 0.964; (g) y = 0.998·e–6.07x, R2 = 0.997. (B): (d) y = 1.12·e–8.59x, R2 = 0.892; (e) y =
0.984·e–3.58x, R2 = 0.938; (f) y = 1.13·e–11.35x, R2 = 0.920; (g) y = 0.997·e–68.82x, R2 = 0.989. Concentrations of Oflx
(MIC, IC50) for free Oflx and Oflx conjugated on a given
sized nanocarrier were determined using the exponential fitting equation
at the half of the maximum of the normalized OD600 nm for
each curve, respectively.