Cells are not isolated units; they continuously exchange proteins, genetic material, and even entire organelles with their neighbors. Intercellular transfer influences how tissues develop, respond to stress, and repair damage. In certain cancers, for example, tumor cells can acquire mitochondria from nearby cells to sustain growth; similar exchanges are also linked to aging processes. However, despite massive advances in gene-editing and molecular-targeting technologies, we still lack the tools to directly and reliably manipulate the cytoplasmic composition of living cells.