Figure 5.

HPPH dose-dependent and cell type-specific PDT response. A co-culture of TEC-1–2 (passage 37) and CSFE-labeled T-Fb (L323) was incubated for 24 h with 800nM HPPH in DMEM-10% FBS and then chased for 24 h in HPPH-free medium. Cellular level of retained HPPH was determined by fluorescent microscopy prior to treatment with therapeutic light (Day 0). The culture was imaged daily for 3 days post PDT to record the reorganization of CSFE-labeled stromal cells and fate of TEC-1–2 cell clusters. HPPH is stably retained by photo-damaged cells and is detectable by fluorescence present in aggregates of killed TEC-1–2 cells. Surviving TEC-1–2 clusters are recognized by the low to non-detectable HPPH fluorescence and physical exclusion of stromal cells from the collagen-support matrix.