In cancer photodynamic therapy (PDT), improved efficiency of photosensitizer delivery to tumors may be obtained by binding them to targetable water soluble polymeric carriers. However, attachment of photosensitizers to Macromolecular carriers may alter their spectral and photosensitizing properties. In this study, a new monosubstituted phthalocyanine derivative, N-glycyl zinc(II) 4,9,16,23-tetraaminophthalocyanine (G-TAPC-Zn) was synthesized by the reaction of zinc(II) 4,9,16,23-tetraaminophthalocyanine (TAPC-Zn) with N-tert-butoxycarbonyl-glycine N'-hydroxybenzotriazole ester followed by deprotection of the tert-butoxycarbonyl (BOC) group. G-TAPC-Zn contains an aliphatic amino group suitable for attachment to water soluble polymeric carriers. By aminolysis of a polymeric precursor, an N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer containing oligopeptide (GFLG) side-chains terminated in p-nitrophenyl ester groups, with G-TAPC-Zn a polymeric derivative of the latter (P-GFLGG-TAPC-Zn) was synthesized. Spectral data indicated that in aqueous solutions P-GFLGG-TAPC-Zn formed aggregates. The degree of aggregation decreased with increasing concentration of detergents or organic solvents in buffer solutions. Consequently, the release of the drug from carrier catalyzed by thiol proteinases, papain or cathepsin B, took place only in the presence of detergents or organic solvents, i.e., under conditions with a lower probability of aggregate formation. Binding of G-TAPC-Zn to HPMA copolymers decreased the quantum yield of singlet oxygen generation from 0.24 to 0.063 and significantly increased its resistance to photobleaching.
在癌症光动力疗法(PDT)中,通过将光敏剂与可靶向的水溶性高分子载体结合,可以提高光敏剂输送到肿瘤的效率。然而,将光敏剂附着到大分子载体上可能会改变它们的光谱和光敏性质。在这项研究中,通过将锌(II)4,9,16,23-四氨基酞菁(TAPC-Zn)与N-叔丁氧羰基-甘氨酸N'-羟基苯并三唑酯反应,然后去保护叔丁氧羰基(BOC)基团,合成了一种新的单取代酞菁衍生物,N-甘氨酰锌(II)4,9,16,23-四氨基酞菁(G-TAPC-Zn)。G-TAPC-Zn含有适合附着到水溶性高分子载体的脂肪族氨基团。通过对聚合物前体进行氨解反应,合成了一种N-(2-羟丙基)甲基丙烯酰胺(HPMA)共聚物,其侧链含有以p-硝基苯酯基团终止的寡肽(GFLG),与G-TAPC-Zn形成的聚合物衍生物(P-GFLGG-TAPC-Zn)。光谱数据表明,在水溶液中,P-GFLGG-TAPC-Zn形成了聚集体。随着缓冲溶液中洗涤剂或有机溶剂浓度的增加,聚集程度减少。因此,在只有洗涤剂或有机溶剂存在的条件下,即聚集体形成概率较低的条件下,药物从载体中由硫蛋白酶、木瓜蛋白酶或半胱氨酸蛋白酶催化的释放才会发生。G-TAPC-Zn与HPMA共聚物的结合降低了单线态氧产生的量子产率,从0.24降至0.063,并显著增加了其对光漂白的抵抗力。