The effect of oxygen on the photobleaching of hematoporphrin monomethyl ether (HMME) in different solutions

摘要

To analyse the effect of oxygen on the photobleaching of HMME, photobleaching rates of HMME when bubbled with oxygen or argon, added with singlet oxygen quenchers or hydroxyl radical quencher were compared. According to the solvents in which HMME was dissolved, four groups were set, HMME-DMSO, HMME-PBS, HMME-Albumin buffer, HMME-Cells suspension. Each group was divided into four subgroups, bubbled with oxygen or argon, added with singlet oxygen quenchers or hydroxyl radical quencher respectively. Spectra measurement was performed at 10min intervals for a period of 40 min before and after laser irradiation, photobleaching rates under different condition were compared. Photobleaching was the fastest when bubbled with oxygen, apparentely inhibited when bubbled with argon or added with singlet oxygen quenchers. Hydroxyl radical quencher can inhibit photopleaching of HMME slightly, but its inhibition was gentler than that of singlet oxygen quenchers and argon. Oxygen plays an inportant role in thre photobleaching of HMME, and the process is singlet oxygen mediated self-sensitized photooxidation.