The cellular zeta potential is the electrical potential a few nanometers beyond the surface of a cell in water, typically thought to arise from fixed surface charges. However, recent evidence suggests that the cell's membrane potential (Vm) can dynamically influence the zeta potential, allowing cells to modulate interactions with their environment. This interaction is significant in various physiological processes, including blood cell function, immune response, development, and cancer. While Vm and zeta potential are rarely studied together, data from multiple studies indicate that they are mechanistically linked. For example, in red blood cells, Vm can modulate zeta potential by about a third of its value. Similar effects have been observed in platelets, where changes in Vm affect ion transport and cell-protein interactions. These findings suggest that Vm-mediated zeta potential changes play a functional role in cell physiology. The zeta potential is also crucial for determining the stability of colloidal solutions and cell-cell interactions. In cancer, altered Vm is associated with increased metastasis, and zeta potential measurements in cancer cells show significant differences compared to healthy cells. In bacteria, zeta potential varies with environmental conditions and cell viability, and changes in Vm can influence zeta potential. In cell differentiation, zeta potential changes are observed, with more polarized values in specialized cells. The study of zeta potential and Vm has implications for understanding cell function and interactions, and further research is needed to fully explore their roles in biological processes.The cellular zeta potential is the electrical potential a few nanometers beyond the surface of a cell in water, typically thought to arise from fixed surface charges. However, recent evidence suggests that the cell's membrane potential (Vm) can dynamically influence the zeta potential, allowing cells to modulate interactions with their environment. This interaction is significant in various physiological processes, including blood cell function, immune response, development, and cancer. While Vm and zeta potential are rarely studied together, data from multiple studies indicate that they are mechanistically linked. For example, in red blood cells, Vm can modulate zeta potential by about a third of its value. Similar effects have been observed in platelets, where changes in Vm affect ion transport and cell-protein interactions. These findings suggest that Vm-mediated zeta potential changes play a functional role in cell physiology. The zeta potential is also crucial for determining the stability of colloidal solutions and cell-cell interactions. In cancer, altered Vm is associated with increased metastasis, and zeta potential measurements in cancer cells show significant differences compared to healthy cells. In bacteria, zeta potential varies with environmental conditions and cell viability, and changes in Vm can influence zeta potential. In cell differentiation, zeta potential changes are observed, with more polarized values in specialized cells. The study of zeta potential and Vm has implications for understanding cell function and interactions, and further research is needed to fully explore their roles in biological processes.