Supporting Information.
(A) The critical aggregation concentration (cac) was determined from the intensity ratio (I343/I338) of the pyrene excitation spectra versus the logarithm of GCD conjugates concentration. 1.3 1.2 1.1
I343/I338
1.0 0.9 0.8 0.7 0.6 0.5 -3
-2
-1
0
1
2
Log C (mg/mL)
Figure S1. Intensity ratio (I343/I338) from pyrene excitation spectra as a function of GCD conjugates concentration in PBS solution (pH 7.4): ({) GCD6, (z) GCD12, (
) GCD22, () GCD30.
(B) The hydrophobicity of the nanoparticle core was estimated by measuring the equilibrium constant Kv for partitioning of pyrene between nanoparticle phase and water, as described previously.34 Assuming a simple equilibrium, the ratio of pyrene in the micellar phase to the water phase ([Py]m/[Py]w) can be expressed as follows; [Py]m/[Py]w = KvVm/Vw where Vm and Vw are the volumes of micellar and water phases, respectively.
(1)
Equation 1 can be rewritten as; [Py]m/[Py]w = KvXbile(c-cac)/1000ρbile
(2)
where Xbile is the weight fraction of deoxycholic acid, c is the concentration of the HD conjugates, and ρbile is the density of the inner core of self-aggregates, which is assumed as that of deoxycholic acid (1.31g/mL).43 [Py]m/[Py]w = (F-Fmin)/Fmax-F)
(3)
where Fmax and Fmin are the intensity ratios (I343/I338) at high and low concentration ranges, in Fig. 2, and F is the intensity ratio (I343/I338) in the intermediate concentration range of the conjugates. By combining eqs 2. and eqs 3, Kv values of pyrene are determined by using a plot (F-Fmin)/Fmax-F) versus the GCD30 concentration as shown in Fig S2.
1.0
(F-Fmin)/(Fmax-F)
0.8
0.6
0.4
0.2
0.0 0.0
0.1
0.2
0.3
0.4
0.5
Concentration (mg/mL)
Figure S2. Plots of (F-Fmin)/Fmax-F) vs concentration of the GCD conjugates in PBS solution (pH 7.4): ({) GCD6, (z) GCD12, (
) GCD22, () GCD30.
(C) For microheterogeneous system such as an aqueous micellar solution, the steadystate quenching data is known to fit in the quenching kinetics as follows; 44, 45 ln(I0/I) = [Q]/[M]
(4)
where I0 and I are the fluorescence intensity in the absence and presence of a quencher, [Q] is the concentration of the quencher, and [M] is the concentration of hydrophobic microdomains in self-aggregates. Thus, [M] can be obtained from the slope of ln(I0/I) = f([Q] and the aggregation number per one hydrophobic microdomain (Nbile) given by eqs 5. Nbile = [DOCA]/[M]
(5)
1.2
1.0
ln(I/Io)
0.8
0.6
0.4
0.2
0.0 0.0
0.2
0.4
0.6
0.8
7
[CPC] X10 M
Figure S3. In(Io/I) of pyrene fluorescence as a function of CPC concentration in the presence of GCD conjugates. [GCD conjugates = 0.1mg/mL] and [pyrene = 6×10-7M]: ({) GCD6, (z) GCD12, (
) GCD22, () GCD30.
