Opaque walled 96 well plates

Cells were implanted in opaque‐walled 96‐well plates (Corning, Toledo, OH, USA), and control wells containing medium without cells were also prepared to obtain a value for background luminescence. A CellTiter‐Glo® Luminescent Cell Viability Assay (Promega, Madison, WI, USA) was applied for ATP measurement. After pretreatment, the plate and its contents were equilibrated at RT for approximately 30 min. Then, 100 μL of CellTiter‐Glo® reagent was added to each well, which was mixed for 2 min on an orbital shaker to induce cell lysis and incubated at RT for 10 min to stabilize the luminescent signal before the luminescence record via a microplate reader (BioTek Synergy H1, Winooski, VT, USA). The average ATP content per cell was calculated in accordance with the cell number in each well.
Encapsulation of ATP with liposomes was carried out according to a published protocol (Verma et al., 2005). Lipofectamine 2000 (Invitrogen) was employed to deliver ATP (Solarbio) into cells as described above.