The pH recovered magnetic cargo solution was adjusted to pH 7.0 and reused in combination with the unconjugated magnetic cargo to treat live Jurkat T cells. Surface conjugation of Jurkat T cells was observed for the combination of recovered cargo to test for reusability (Figure ). To estimate the extent of reusability, we performed the surface conjugation-disruption-reconjugation several times. We observed that our cargo can be reused at least two times in a reversible manner with the magnetically isolated reagent unlike a one-time use of existing reagents for live-cell imaging. To see whether the covalent cargo 2 can facilitate cell-cell interaction, we treated Jurkat T cells with this cargo for 30 minutes and then acquired bright-field images of both the un-treated and cargo treated Jurkat T cells. This data revealed that untreated Jurkat T cells predominately exist as isolated cells in culture whereas cargo 2 treated Jurkat T cells formed clusters, indicating -cellcell interactions (Figure ). Fluorescence images of the Jurkat T cells also revealed both cell-cell conjugation (Figure ) and cell-cell clustering (Figure ) phenomena for the cargo 2 treatment. To verify our cell-cell interactionbased proliferation hypothesis, we treated 10 µg/mL of the covalent cargo 2 with Jurkat T cells and performed a 3 days proliferation assay. We compared the results with cell culture growth media as vehicle control and the percentage of live cells in a cargo-treated sample was calculated relative to the vehicle control. We observed a statistically significant increase of ~20% in the number of Jurkat T cells tread with cargo 2. To use our dual conjugation chemical strategy for enhancing the manufacturing of cell therapies, we functionalized magnetic beads to the cargo, since magnetic cargo molecule provides a simple method to separate cells from that cargo molecule (Figure ). This process can be repeated several times for faster proliferation of therapeutic cells and to retrieve the original cell culture every time (Figure ). Thus, our cell conjugation method can be used reversibly to induce cell-cell communication and it is a much easier approach as compared to the other recently developed time-consuming and expensive methods such as DNA-programmed assembly of cells (DPAC). Finally, we were interested to study the change in proliferation and clustering of T cells with time. We recorded realtime videos of conjugated and unconjugated Jurkat T cells by the IncuCyte live-cell analysis system that suggests an increase in clustering of surface conjugated T cells compared to vehicle treatment or no cargo control (Figure ). Thus, our data clearly suggest the cargo reagent can reversibly functionalize cell membranes and can enhance cell-cell interactions which lead to an increase in the proliferation of therapeutic cells for bio-manufacturing.