血卟啉衍生物与人血清白蛋白作用的光谱特性研究

研究了用于光动力学诊断和治疗的光敏剂血卟啉衍生物（HpD）、人血清白蛋白（HSA）及其复合物的光谱特性。HpD与HSA作用形成HSA-HpD复合物大分子，其吸收光谱主峰（402nm）和荧光发射光谱主峰（622nm）与纯HpD的主峰相比都红移了8nm以上。当使用对应HSA的激发峰228和279nm及HpD的激发峰394nm的光源，分别激发HpD-HSA混合体系时，发现体系中的HSA与HpD的吸收对复合大分子在622nm的荧光发射均有贡献。当使用对应HpD-HSA吸收峰的激发波长402，502，537和570nm，分别对HpD-HSA体系进行激发时，发现402nm波长对该体系的荧光激发效率最佳，且吸收次峰537和570nm对HpD-HSA的激发效率则明显高于纯HpD水溶液体系。实验结果表明，在肿瘤的临床诊断和治疗中选择合适的激发波长和荧光接收波长时，应考虑HpD与体内的特征蛋白结合后发生的光谱红移。该研究结果同时预示，当选用穿透能力较强的长波吸收次峰对肿瘤组织进行激发时，其激发效率应高于体外该波长激发单纯HpD水溶液体系的效率。

Spectral Properties of Hematoporphyrin Derivative after Interacted with Human Serum Albumin

The spectral properties of photosensitizer HpD,human serum albumin(HSA) and their complex have been studied.The(results) show that HpD can form HpD-HSA complex with HSA in physiological condition.Compared with pure HpD,the maximum(absorption) and the fluorescence peaks for HpD-HSA complex had 8-10 nm red-shift.When HpD-HSA complex was excited by the light of corresponding to excitation peaks of HSA(228 and 279 nm) and HpD(394 nm),it was found that the absorption of HSA and HpD both contributed to the emission of HpD-HSA complex at 622 nm. The complex of HpD-HSA was individually excited by wavelengths corresponding to HpD absorption peaks of 402,502,537 and 570 nm,and the excitation efficiency of HpD-HSA at pumping(wavelength) of 537 and 570 nm was higher than that of HpD.The results demonstrate that the red-shift caused by the interaction of HpD and the special proteins in blood should be considered in selecting the excitation and emission wavelength in photodynamic(diagnosis) and therapy.The results also indicate that the excitation efficiency of porphyrin-protein complex in vivo is higher than that of HpD in vitro when a longer wavelength light corresponding to the week absorption peaks of porphyrin-protein complex is used in (photodynamic) therapy.