In the original paper,1 the zeta potential values for the EA926 cultured cells alone (deconvolved) and the HEK cultured cells alone (deconvolved) were reported incorrectly. The correct zeta potential values for the HEK cultured cells alone (deconvolved) and the EA926 cultured cells alone (deconvolved) are –10.56 ± 5.7 mV and –11.04 ± 1.2 mV, respectively. These corrected values should be considered when reviewing the text, Table I, Figures 4 and 5.
Results from normal streaming potential device. Phosphate buffered solution (PBS) with a conductivity of 1.81 mS/cm and 7.4 pH was used as the initial feed solution.
| Case | Streaming potential SP (mV kPa−1) | Zeta potential ζ (mV) | Range of pressures P (kPa) | Hydraulic permeability LP (cm2 s g−1) × 109 |
|---|---|---|---|---|
| DMEM soaked (membrane only) | −36.1 ± 2.0 | −7.9 ± 0.44 | 23–127 | 28.9 ± 3.72 |
| EA926 seeded with membrane | −52.1 ± 4.6 | −11.44 ± 1.00 | 31–66 | 9.0 ± 8.24 |
| HEK seeded with membrane | −51.4 ± 1.6 | −11.30 ± 0.34 | 17–66 | 2.2 ± 1.99 |
| EA926 cultured cells alone (deconvolved) | N/A | −11.04 ± 1.2 | N/A | N/A |
| HEK cultured cells alone (deconvolved) | N/A | −10.56 ± 5.7 | N/A | N/A |
| Case | Streaming potential SP (mV kPa−1) | Zeta potential ζ (mV) | Range of pressures P (kPa) | Hydraulic permeability LP (cm2 s g−1) × 109 |
|---|---|---|---|---|
| DMEM soaked (membrane only) | −36.1 ± 2.0 | −7.9 ± 0.44 | 23–127 | 28.9 ± 3.72 |
| EA926 seeded with membrane | −52.1 ± 4.6 | −11.44 ± 1.00 | 31–66 | 9.0 ± 8.24 |
| HEK seeded with membrane | −51.4 ± 1.6 | −11.30 ± 0.34 | 17–66 | 2.2 ± 1.99 |
| EA926 cultured cells alone (deconvolved) | N/A | −11.04 ± 1.2 | N/A | N/A |
| HEK cultured cells alone (deconvolved) | N/A | −10.56 ± 5.7 | N/A | N/A |
Representative graphs comparing the measured zeta potential (ζ) for three membrane cases: virgin polycarbonate membranes, HEK confluent cell seeded membrane and EA926 confluent cell seeded membrane, and the deconvolved confluent cells. Using Eq. (9), the zeta potential (ζc) of the HEK cells and EA926 cells was deconvolved from the cell-membrane configurations.
Representative graphs comparing the measured zeta potential (ζ) for three membrane cases: virgin polycarbonate membranes, HEK confluent cell seeded membrane and EA926 confluent cell seeded membrane, and the deconvolved confluent cells. Using Eq. (9), the zeta potential (ζc) of the HEK cells and EA926 cells was deconvolved from the cell-membrane configurations.
Comparing the zeta potential of EA926 and HEK cells deduced from the streaming potential measured using our streaming potential device and that measured using commercially available Malvern Zetasizer®.
Comparing the zeta potential of EA926 and HEK cells deduced from the streaming potential measured using our streaming potential device and that measured using commercially available Malvern Zetasizer®.
The error came about due to our inadvertently using the ratio |$\frac{{{{\bm L}_P} _m }}{{{{\bm L}_P} _{m + c} }}$| instead of |$\frac{{{{\bm L}_P} _{m + c} }}{{{{\bm L}_P} _m }}$| in Eq. (9) to calculate the streaming potential of the confluent cell layer. In a sense, this error is instructive in enlightening users that when the hydraulic permeability of the confluent cell layer, LPm + c, is significantly lower than the hydraulic permeability of the membrane, LPm, by inspection of Eq. (9), the measured streaming potential is approximately the same as the streaming potential of the confluent cells alone.
