Photosensitive Aluminum Phthalocyanine And Chemotherapy Drugs Doxorubicin In The Treatment Of Tumor Synergy Research

Photodynamic Therapy (PDT) is a new cancer-treating technique which came out in the late1970s and developed very fast in recent years. It is a kindof light-sensitive reaction with oxygen, following biological effect. PDT is a new method which bases on the reaction among photosensitizer, laser and oxygen.Photosensitizer is one of the most important influencing-factor of PDT effect, so the research of photosensitizer is critically important to the effect of PDT. Photosensitizer have been developed for three stages till now. Among the second photosensitizer, Metal-phthalocyanines (Mpcs) because of its unique properties such as high quantum yield, high singlet oxygen yield and intense absorption in the red and rear infra-red region of solar spectrum is very popular. Some of them have been approved for clinical application already, However, its low speed of entering cells greatly decreased its PDT effect. So searching a method which could faster its speed is very important. One way is to develop a new kind of photosensitizer; the other way is making use of a kind of carrier to help it entering cells.Sulfonated aluminum phthalocyanine (AlPcS), a popularly used photosensitizer for photodynamic therapy of cancers (PDT), was linked with the anti-cancer drug Doxorubicine (Dox) by the electrostatic binding. The fluorescence resonance energy transfer (FRET) from Dox to AlPcS demonstrated the formation ofAlPcS-Dox conjugates, as the fluorescence intensity of conjugated Dox was decreased and that of AlPcS moiety was enhanced. The AlPcS-Dox conjugation was further confirmed by the experiment of electrophoresis. The AlPcS-Dox improved the cellular uptake by transporting3times and4times AlPcS into RBL (rat basophilic leukemia) and QGY (human hepatocellular carcinoma) cancer cells respectively compared to un-conjugated AlPcS. In contrast with the damaging effect of AlPcS or Dox alone, the AlPcS-Dox remarkably increased the killing efficacy on those cells demonstrating the benefit of the synergistic effect of AlPcS and Dox. These results suggest that the combination of different anti-cancer drugs is a suitable strategy to improve the cancer therapy.