Figure 3. Dose dependent response from single cells after cytoplasmic delivery of IP3.

(A) Histogram plot showing the percent calcium activation as measured using fluo-3 versus the average concentrations of IP₃ contained within the 100nm lipid nanocapsules. The blue bars show the fraction of cells exhibiting a calcium response, including both sustained and transient calcium increases. The red bars show only those cells that exhibited a transient calcium increase. At the 90 µM of IP₃, the majority of calcium responses was transient, in sharp contrast to the 370 µM result where nearly all responses were sustained. All measurements were performed at 2.5 hours after the start of lipid nanocapsule loading, with the exception of the 730* results, which were obtained at the 1-hour time point after loading was initiated. Total N = 150 cells for each bar (50 cell activation attempts over 3 days for each bar). (B) Plots showing the increase in calcium as a function of time, illustrating examples of sustained and transient responses. The control indicates photolysis of an empty vesicle. The cells used for these experiments were CHO-M1.