The effect of NaCl on the self-assembly of elastin-

like block co-recombinamers: Tuning the size of

micelles and vesicles

Guillermo Pinedo-Martín, Mercedes Santos, Ana M. Testera, Matilde Alonso, J. Carlos

Rodríguez-Cabello.

Bioforge Group, University of Valladolid, CIBER-BBN, Paseo de Belén 11, 47011

Valladolid, Spain.

Corresponding author: roca@bioforge.uva.es

Determination of the Refractive Index (nD) and the Specific Refractive Index

Increment (dn/dc).

Measurements of the refractive index value (nD) at 589.3 nm (Sodium D-line) were

carried out using a digital refractometer (Mettler Toledo RE50, Mettler-Toledo GmbH,

Schwerzenbach, Switzerland) with a Peltier thermostat that kept the samples at the

working temperature to an accuracy of 0.02 °C. The apparatus was calibrated by

measuring the refractive index of Millipore quality water. A minimum of three

independent readings were taken for each composition. Standard uncertainties of

measurements were established to be less than 5.0 × 10-5. The nD was studied

experimentally for the three amphiphilic ELbcRs in a wide range of concentrations (1-8

mg/ mL) and NaCl concentrations (0-0.25M). Figure S1 shows the linear dependence of

nD with concentration for E100A40 solutions at different NaCl concentrations. The

plots for the other two ELbcRs are similar (figures not shown).

Figure S1. NaCl concentration dependence of nD for E100A40

The value of the specific refractive index increment (dn/dc) was deduced from the slope

of plots of the refractive index versus concentration for each ELbcR

The results are listed in Table S1.

Table S1. Specific refractive index increments, dn/dc, for E50A40, E100A40 and

E50A40E50 in aqueous solution at NaCl concentrations.

ELbcR\[NaCl] 0.25M 0.125M 62.5mM 31.25mM 15.625mM

E50A40 0.161 0.158 0.158 0.162 0.159

E100A40 0.165 0.160 0.164 0.164 0.162

E50A40E50 0.162 0.159 0.158 0.160 0.160

The differences between them are minimal. Thus a dn/dc of 0.160 ml.g -1 was used for

the three recombinamers

Static Light Scattering:

FigureS2: Berry plots for E50A40, E100A40 and E50A40E50 in 62.5 mM aqueous

NaCl solution

Cryo-TEM:

Figure S3: Cryo-TEM images of the self-assembled nanoparticles: A) E50A40,

B) E100A40, C) E50A40E50 in a 62.5 mM NaCl solution.