Figure 8. Micropatterned P surfaces impart a high degree of spatiotemporal control over MGC formation.

(A) Schematic of the method used to create micropattered paraffin prints on glass. Five microliters of a 1 mg/mL solution of paraffin in toluene is dispensed onto the glass surface and a finder grid is placed on the drop. After the solution dries the cover glass is plasma cleaned and only surface covered by the print remains fusogenic. (B) Phase-contrast micrographs show the formation of MGCs on the micropattern. Time (hours:min:sec) is shown in the top right corner of each micrograph. The scale bars are 50 μm. In the final still frame, blue corresponds to Hoechst 33342, which labels nuclei. (C) Correlated light and scanning electron microscopy views of a micropatterned P surface show MGC formation from a mixture of eGFP- and mRFP-LifeAct cells. The scale bar corresponds to 25 μm. (D) Shown are the kinetics of fusion events for 8 hr on the micropatterned P and Permanox surfaces after the onset of fusion (i.e. 9.5 hr after the application of IL-4). Results shown are means ± S.D. from three independent experiments. (E) Quantification of the types of fusion events during MGC formation on the micropatterned P and Permanox surfaces for 8 hr after the onset of fusion. The data are expressed as percent of the total number of fusion events detected on each surface and are means ± S.D. from three experiments. (F) The kinetics of type 1, 2 and 3 fusion events on the micropatterned P surface for 8 hr after the onset of fusion. The data shown are means ± S.D. from three experiments. A 20× field corresponds to 578 × 433 μm.