Spectroscopic Methods in Comparing the Interaction of Chlorin e6,Liposome-chlorin e6 and Bovine Serum Albumin

TONG Yumeng; HAN Feifei; XU Chenchen; YANG Fang; WANG Xiyu; LIU Jinmi; LIU Yuchen; WANG Haiping

doi:10.13730/j.issn.2097-2148.2025.04.003

Abstract：Objective To explore the advantages of liposome photosensitizers in cancer patients with the treatment of photodynamic therapy(PDT)from the perspective of the interaction between photosensitizers and bovine serum albu-min(BSA).Methods The interaction,binding constant,binding site and binding mode of the photosensitizer chlorin e6(Ce6)and liposome-Ce6(Lipo-Ce6)with BSA were studied using spectroscopic methods.The two photosensitizers were injected into the tail vein of mice,and the concentration of photosensitizer in the serum was measured at different timing to investigate the metabolic pattern of the two forms of photosensitizers in mice.Results The spontaneous binding of BSA to both Ce6 and Lipo-Ce6 was demonstrated,the binding constant between Ce6 and BSA was 3.111 × 105,and the number of binding site was 1.204;the binding constant between Lipo-Ce6 and BSA was 1.644 × 102,the binding site was 0.549,the fluorescence quenching mode of BSA by Ce6 and Lipo-Ce6 was static.The effect of Ce6 on the polar environ-ment in the vicinity of the Tryptophan(Trp)residues was more pronounced,while the effects of Lipo-Ce6 on the polar environment in the vicinity of both Trp and Tyrosine(Tyr)residues was more significant.The fluorescence intensity of Lipo-Ce6 in serum also decreased by time,but the decline rate was much slower than that of dissociate Ce6,the decrea-sing trend of drug concentration in the blood of mice in the Ce6 group was more obvious than that in the Lipo-Ce6 group(P＜0.05).Lipo-Ce6 had longer circulation time than Ce6 in the blood of mice.Conclusion Both Ce6 and Lipo-Ce6 have the capacity to bind to BSA,however,the degree of binding between Lipo-Ce6 and BSA is less than that with Ce6,liposomes have certain protective effect on Ce6,which can improve the efficiency of drug entry into the le-sion site.