Table 3. Parameters measured for silk nanoparticles dispersed in 10 mM sodium phosphate buffer (pH 7.4) derived from electrical asymmetric flow field-flow fractionation (EAF4)-MALS. Two-way ANOVA and Šídák's multiple comparisons test were used, comparing day 56 and 0 data: p < 0.05 (*), p < 0.01 (**), p < 0.001 (***), and p < 0.0001 (****). Abbreviations: peak 1 (P1); peak 2 (P2); hydrodynamic radius (Rh); radius of gyration (Rg); dynamic light scattering (DLS); zeta potential (ZP); no data available (NA).
| Silk nanoparticle | Applied current (mA) | Elution time (min) | MALS-Rg (nm) | DLS-Rh (nm) | R g/Rh | ||||
|---|---|---|---|---|---|---|---|---|---|
| P1 | P2 | P1 | P2 | P1 | P2 | P1 | P2 | ||
| Day 0 | |||||||||
| 0 mg cation | +0.2 | 17.7 (±0.4) | 37.0 (±0.1) | 24.6 (±0.1) | 46.1 (±0.1) | 33.7 (±2.6) | 73.4 (±13.9) | 0.73 (±0.06) | 0.64 (±0.14) |
| 0 | 18.9 (±0.3) | 37.7 (±0.1) | 24.5 (±0.1) | 45.5 (±1.0) | 35.9 (±9.8) | 79.1 (±3.3) | 0.73 (±0.23) | 0.57 (±0.01) | |
| −0.2 | 20.2 (±0.9) | 38.4 (±0.1) | 24.4 (±0.1) | 45.8 (±0.6) | 31.6 (±4.3) | 76.4 (±16.4) | 0.78 (±0.10) | 0.62 (±0.14) | |
| 0.7 mg Ca2+ | +0.2 | 21.3 (±0.2) | 37.3 (±0.1) | 24.7 (±0.1) | 51.7 (±0.3) | 38.0 (±5.3) | 94.5 (±5.3) | 0.66 (±0.10) | 0.64 (±0.11) |
| 0 | 22.1 (±0.1) | 37.9 (±0.1) | 24.6 (±0.1) | 51.9 (±0.3) | 33.5 (±9.1) | 81.8 (±12.8) | 0.77 (±0.18) | 0.55 (±0.03) | |
| −0.2 | 23.3(±0.3) | 38.5 (±0.0) | 24.6 (±0.1) | 50.0 (±0.3) | 31.6 (±3.7) | 87.5 (±4.5) | 0.79 (±0.09) | 0.57 (±0.03) | |
| 1.1 mg K+ | +0.2 | 20.4 (±0.4) | 37.5 (±0.0) | 24.7 (±0.1) | 57.7 (±0.6) | 50.4 (±9.2) | 89.2 (±6.3) | 0.50 (±0.10) | 0.65 (±0.04) |
| 0 | 21.5 (±0.5) | 38.2 (±0.0) | 24.4 (±0.1) | 55.5 (±0.4) | 31.6 (±4.1) | 93.0 (±0.7) | 0.78 (±0.10) | 0.60 (±0.01) | |
| −0.2 | 22.7 (±0.3) | 38.8 (±0.1) | 24.3 (±0.1) | 53.2 (±0.6) | 25.3 (±2.4) | 85.3 (±5.1) | 0.97 (±0.10) | 0.63 (±0.03) | |
| Day 56 | |||||||||
| 0 mg cation | +0.2 | 25.9 (±0.1)**** | 37.5 (±0.1)**** | 27.9 (±0.3)**** | 62.2 (±1.3)**** | 31.4 (±14.0) | 8.0 (±5.8)**** | 0.99 (±0.35) | 18.30 (±21.95)** |
| 0 | 30.3 (±0.3)**** | 38.1 (±0.1)**** | 29.5 (±0.3)**** | 61.8 (±0.3)**** | 56.5 (±11.7) | 78.3 (±42.6) | 0.54 (±0.12) | 0.94 (±0.44) | |
| −0.2 | 29.8 (±0.8)**** | 38.7 (±0.1)**** | 29.3 (±0.3)**** | 56.7 (±0.3)**** | 65.9 (±34.4)* | 136.7 (±108.8)**** | 0.57 (±0.37) | 1.38 (±1.88) | |
| 0.7 mg Ca2+ | +0.2 | 26.3 (±0.5)**** | 37.5 (±0.1)* | 27.9 (±0.3)**** | 62.5 (±1.4)**** | 45.0 (±6.1) | 102.7 (±2.3) | 0.63 (±0.08) | 0.61 (±0.02) |
| 0 | 26.6 (±0.0)**** | 38.0 (±0.1) | 28.0 (±0.2)**** | 59.1 (±0.6)**** | 48.3 (±19.9) | 103.5 (±10.2) | 0.64 (±0.21) | 0.57 (±0.05) | |
| −0.2 | 26.6 (±0.0)**** | 38.7 (±0.0)** | 27.8 (±0.1)**** | 54.3 (±0.4)**** | 39.7 (±9.9) | 99.9 (±5.7) | 0.73 (±0.17) | 0.54 (±0.03) | |
| 1.1 mg K+ | +0.2 | 28.4 (±0.3)**** | 37.3 (±0.1)* | 29.5 (±0.2)**** | 52.2 (±0.5)**** | 42.2 (±4.1) | 102.7 (±2.3) | 0.70 (±0.07) | 0.51 (±0.01) |
| 0 | 29.0 (±0.4)**** | 37.8 (±0.0)**** | 29.1 (±0.1)**** | 50.0 (±0.3)**** | 52.9 (±19.1) | 103.7 (±9.0) | 0.61 (±0.25) | 0.48 (±0.04) | |
| −0.2 | 29.6 (±0.6)**** | 38.2 (±0.1)**** | 29.0 (±0.2)**** | 46.1 (±0.2) | 45.5 (±7.4) | 102.1 (±5.1) | 0.65 (±0.11) | 0.45 (±0.02) | |