Empirical Modeling of Cancer Cell Viability in Oxygen-Mediated Photodynamic Therapy

Author(s): Kuo-Ti Chen, Jui-Teng Lin, Hsia-Wei Liu

The dynamic roles of photosensitizer (PS) concentration and light intensity were measured and analyzed empirically. The efficacy of photodynamic therapy (PDT) and cell viability (CV) are measured (in vitro) and analyzed by analytic and numerical modeling. For a fixed PS concentration, CV is a nonlinear deceasing function of light intensity and exposure time; for a fixed light intensity, higher PS concentration achieves higher efficacy or smaller CV (at steady-state), in consistent to our analytic formulas. The anticancer efficacy may be improved by various strategies such as resupply of Ce6, external oxygen, or stabilizing the singlet oxygen (with increased lifetime).