Much attention has been paid to water-soluble porphyrins and metalloporphyrins as potential sensitizers for photodynamic therapy (PDT). Thus, water-soluble tricationic phosphorus porphyrin complexes were prepared via the introduction of an N-alkylpyridinio group on the axial ligands of phosphorus porphyrins. The resulting tricationic phosphorus porphyrins readily dissolve in aqueous solutions without the formation of aggregates, even at high concentration. Moreover, the affinity of the porphyrins to human serum albumin (HSA) is a key factor in their application to PDT since HSA plays an important role in the transport of drug molecules to a target cell. Interactions between the tricationic phosphorus porphyrins and HSA were examined on the basis of changes in the Soret bands of the absorption and fluorescence spectra of phosphorus porphyrin solutions in the presence of HSA and the fluorescence quenching of HSA by the tricationic phosphorus porphyrins. Tricationic phosphorus porphyrins with moderately long alkyl chains on the pyridinio group were strongly adsorbed on the HSA at a position near the tryptophan residue of HSA. This result suggests that tricationic phosphorus porphyrins containing alkyl groups are good candidates as PDT reagents because of their high water solubility and high affinity for HSA.
人们对
水溶性
卟啉和
金属
卟啉作为光动力疗法(PDT)潜在的光敏剂给予了高度关注。因此,通过在
磷卟啉的轴向
配体上引入N-烷基
吡啶锵基团,制备了
水溶性三阳离子
磷卟啉配合物。所得到的三阳离子
磷卟啉容易溶解在
水中,不会形成聚集,即使在较高浓度下也是如此。此外,
卟啉对人类
血清白蛋白(H
SA)的亲和力是其在PDT应用中的一个关键因素,因为H
SA在药物分子向目标细胞的转运中起着重要作用。通过考察在存在H
SA的情况下,
磷卟啉溶液的吸收和荧光光谱中Soret带的改变以及三阳离子
磷卟啉对H
SA的荧光淬灭作用,研究了三阳离子
磷卟啉与H
SA的相互作用。含适度长烷基链的
吡啶锵基团上的三阳离子
磷卟啉在H
SA的色
氨酸残基附近位置强吸附。这一结果表明,含有烷基基团的三阳离子
磷卟啉由于其高
水溶性和对H
SA的高亲和力,是作为PDT试剂的良好候选。