Luo Y, Ziebell M R, Prestwich G D
Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112-5820, USA.
Biomacromolecules. 2000 Summer;1(2):208-18. doi: 10.1021/bm000283n.
A cell-targeted polymeric prodrug prepared from Taxol and chemically modified hyaluronic acid (HA) was evaluated in vitro. Herein we report four results in support of the selective uptake and targeted toxicity of the HA-Taxol prodrug. First, a fluorescently labeled HA-Taxol (FITC-HA-Taxol) was synthesized and used to demonstrate cell-specific binding and uptake using flow cytometry and confocal microscopy. Second, the selective cytotoxicity of FITC-HA-Taxol allowed direct correlation of uptake with selective cytotoxicity. Third, the rapid uptake and selective cytotoxicity of HA-Taxol bioconjugates could be blocked by either excess HA or by an anti-CD44 antibody, but not by chondroitin sulfate (CS). Finally, the release of free Taxol from HA-Taxol in human plasma or in cell culture media revealed that the free drug was hydrolytically released from the bioconjugate by cleavage of the labile 2' ester linkage. Taken together, these data support the notion that the targeted cytotoxicity of HA-Taxol bioconjugates requires receptor-mediated cellular uptake of the bioconjugate followed by hydrolytic release of free Taxol.
对一种由紫杉醇和化学修饰的透明质酸（HA）制备的细胞靶向聚合物前药进行了体外评估。在此，我们报告了四项结果，以支持HA-紫杉醇前药的选择性摄取和靶向毒性。首先，合成了一种荧光标记的HA-紫杉醇（FITC-HA-紫杉醇），并用于通过流式细胞术和共聚焦显微镜证明细胞特异性结合和摄取。其次，FITC-HA-紫杉醇的选择性细胞毒性使摄取与选择性细胞毒性直接相关。第三，HA-紫杉醇生物共轭物的快速摄取和选择性细胞毒性可被过量的HA或抗CD44抗体阻断，但不能被硫酸软骨素（CS）阻断。最后，HA-紫杉醇在人血浆或细胞培养基中释放游离紫杉醇表明，游离药物通过不稳定的2'酯键的裂解从生物共轭物中水解释放。综上所述，这些数据支持以下观点：HA-紫杉醇生物共轭物的靶向细胞毒性需要生物共轭物通过受体介导的细胞摄取，随后游离紫杉醇水解释放。
