A new application of Gompertz function in photohemolysis: the effect of temperature on red blood cell hemolysis photosensitized by protoporphyrin IX

Photosensitization by protoporphyrin IX (PpIX) is accelerated at different irradiation temperatures, different dark incubation temperatures (T _inc) and different irradiation times. The applicability of Gompertz function to the fractional photohemolysis ratio, a and the rate of fractional photohemolysis, b is found to be the most appropriate model to fit the experimental data with minimum parameters and minimum errors. The reduction in Gompertz parameters, the fractional ratio values of a, and increase in the fractional rate values b, for 20 μM PpIX irradiated with black light at low irradiation temperature 5°C and higher T _inc 37°C was noticed. The parameter a has higher values at lower irradiation time and lower irradiation temperatures which indicates a longer photohemolysis process and longer t ₅₀. Values of the parameter b were found to be strongly temperature-dependent, and always increase with increasing irradiation time and T _inc with lower values at lower irradiation time and lower T _inc. There are no significant changes in the lysis of RBCs process at irradiation temperatures equal to or higher than 35°C. Similarly, no significant change on t ₅₀ at higher irradiation time at T _inc 24 and 37°C. In conclusion, Gompertz analysis technique adapts to study the photohemolysis process at different conditions as a best-fit model.