Scasnár V, van Lier J E
MRC Group in the Radiation Sciences, Faculty of Medicine, University of Sherbrooke, Quebec, Canada.
Nucl Med Biol. 1993 Apr;20(3):257-62. doi: 10.1016/0969-8051(93)90046-w.
Phthalocyanines have been advanced as photosensitizers for the photodynamic therapy of cancer and selectively sulfonated derivatives have shown promise as tumor imaging agents. In order to study the effect of the degree of sulfonation on their biodistribution pattern, we prepared a series of sulfophthalocyanines (PcS) labeled with 67Ga. Direct chelation of metal free phthalocyanines with 67Ga gave chelates which demetallated on further purification whereas condensation of 67Ga with phthalic acid precursors, following purification and fractionation on Sep-Pak C18 cartridges, gave stable products. The distribution pattern of the [67Ga]GaPcS among human plasma proteins was strongly affected by the degree of sulfonation of the PcS. The lower sulfonated GaPcS showed significant binding to the various lipoprotein fractions whereas increased sulfonation favored association to albumin. The use of the 67Ga allowed for the validation of spectrophotometric quantification of GaPcS in biological samples and confirmed the in vivo stability of the radiolabeled complex.
酞菁已被用作癌症光动力治疗的光敏剂，选择性磺化衍生物已显示出作为肿瘤成像剂的前景。为了研究磺化程度对其生物分布模式的影响，我们制备了一系列用67Ga标记的磺化酞菁（PcS）。无金属酞菁与67Ga直接螯合得到的螯合物在进一步纯化时会脱金属，而在Sep-Pak C18柱上纯化和分级分离后，67Ga与邻苯二甲酸前体缩合得到稳定的产物。[67Ga]GaPcS在人血浆蛋白中的分布模式受PcS磺化程度的强烈影响。磺化程度较低的GaPcS与各种脂蛋白组分有显著结合，而磺化程度增加则有利于与白蛋白结合。使用67Ga可以验证生物样品中GaPcS的分光光度法定量，并证实放射性标记复合物在体内的稳定性。
