Talaporfin sodium binding and photocytotoxicity of photosensitization reaction on myocardial cell under various albumin concentrations and temperature

To understand the efficiency change of the extracellular photosensitization reaction by the external factor in myocardium interstitial space, we studied the efficiency change of the extracellular photosensitization reaction caused by talaporfin sodium binding with serum proteins under various serum proteins concentrations and temperature conditions. Talaporfin sodium Q band absorbance was measured with various albumin concentrations and the cell survival rate was measured by WST assay in the same conditions. The talaporfin sodium binding ratio with albumin, high-density lipoprotein, and low-density lipoprotein were measured by talaporfin sodium absorbance measurement after the ultrafiltration. The albumin concentration affects the photocytotoxicity strongly when the albumin concentration was over 2.1 mg/ml in the case of the extracellular photosensitization reaction. It would be useful to measure the peak wavelength in Q band absorbance was suggested to know the albumin concentration and the photocytotoxicity efficiency to realize the safety treatment. The binding ratios with high-density lipoprotein and low-density lipoprotein were decreased with the solution temperature rise from 17°C to 37 °C and the photocytotoxicity was increased with temperature rise from 17°C to 37°C involving this binding ratio change. It would be important to maintain the target organ temperature during the photosensitization reaction to keep the photosensitization reaction efficiency.