Fig. 4. Spheroid toxicity at varying penetration depths using a LIVE/DEAD® assay and imaging live (green) and dead (red) cells using a confocal laser scanning microscope. (A) Confocal images after incubating spheroids with either no DOX (control), or DOX-loaded P(L)LA10K-b-PEG10K, P(L)LA10K-b-POEGMA47510K, or P(L)LA10K-b-POEGMA200010K for 72 h and staining with LIVE/DEAD®. (B) Ratio of green : red fluorescence (live : dead ratio) within the z-projections for each spheroid. n = 3 per formulation tested, ns not significant, *p < 0.05.
