Study of the concentration,
size, and MexAB-OprM dependent inhibitory
effects of antibiotic nanocarriers (AgMUNH-Oflx NPs) on the growth
of (A–D) WT and (E–H) ΔABM cells. (A–D)
Images of the modified LB medium cultured (a) without cells (blank
control) and with WT cells containing (b–i) 0, 0.2, 0.4, 0.6,
0.8, 1.08, 1.62, 2.16 μM (A) unconjugated free Oflx alone and
(b–h) 0.2, 0.4, 0.6, 0.8, 1.08, 1.62, 2.16 μM Oflx conjugated
with Ag NPs of (B) 2.4 ± 0.7, (C) 13.0 ± 3.1, and (D) 92.6
± 4.4 nm in diameter, respectively. (E–H) Images of the
modified LB medium cultured (j) without cells (blank control) and
with ΔABM cells containing (k–r) 0, 0.02, 0.04, 0.06,
0.08, 0.11, 0.14, and 0.27 μM (E) unconjugated free Oflx alone
and (k–r) 0.02, 0.04, 0.06, 0.08, 0.11, 0.14, and 0.27 μM
Oflx conjugated with the Ag NPs of (F) 2.4 ± 0.7, (G) 13.0 ±
3.1, and (H) 92.6 ± 4.4 nm in diameter, respectively. The concentrations
of Oflx conjugated onto the NPs are determined based on their conjugation
ratios in Table 1.
The concentration of AgMUNH2 NPs in (i) of (B–D)
and (r) of (F–H) contain the same concentration of NPs as that
in (h) and (q) for each type of NP in (B–D) and (F–H)
but without Oflx (control experiments to study the effects of AgMUNH2 NPs).