Synthesis, cellular transport, and activity of polyamidoamine dendrimer-methylprednisolone conjugates
Synthesis, cellular transport, and activity of polyamidoamine dendrimer-methylprednisolone conjugates
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DOI：
10.1021/bc0498018
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发表时间：
2005-03-01
影响因子：
4.7
通讯作者：
Kannan, RM
中科院分区：
文献类型：
--
作者：
Khandare, J;Kolhe, P;Kannan, RM
树枝状聚合物由于其良好的尺寸和可剪裁性而成为有前途的多功能药物递送纳米材料。我们比较了两种制备甲基强的松龙（MP）聚酰胺-胺树状大分子（PAMAM-G4-OH）偶联物的方案。谷氨酸（GA）用作间隔子以促进缀合。在方案A中，首先将PAMAM-G4-OH偶联至GA，然后进一步与MP缀合以获得PAMAM-G4-GA-MP缀合物。该方案产生了较低的共轭率的MP，大概是因为较低的反应性和空间位阻的类固醇在拥挤的树枝状聚合物周边。在方案B中，通过首先制备MP-GA缀合物，然后将其偶联至PAMAM-G4-OH树枝状聚合物来克服这种空间位阻。来自方案B的缀合物的1H-1 NMR光谱表明12个MP分子与树枝状聚合物的缀合，对应于32重量%的有效载荷。此外，缀合物进一步用氟代异硫氰酸酯（FITC）荧光标记以评价细胞进入的动力学。流式细胞术和UV/可见光谱分析表明，缀合物在细胞内被迅速吸收。用缀合物处理的A549人肺上皮癌细胞上的荧光和共聚焦显微镜图像显示缀合物主要定位于胞质溶胶中。MP-GA-树枝状聚合物缀合物显示出与游离MP相当的药理活性，如通过抑制前列腺素分泌所测量的。这些缀合物可以潜在地进一步与靶向部分缀合以将药物递送至体内特定细胞。
Dendrimers have emerged as promising multifunctional nanomaterials for drug delivery due to their well-defined size and tailorability. We compare two schemes to obtain methylprednisolone (MP)polyamidoamine dendrimer (PAMAM-G4-OH) conjugate. Glutaric acid (GA) was used as a spacer to facilitate the conjugation. In scheme A, PAMAM-G4-OH was first coupled to GA and then further conjugated with MP to obtain PAMAM-G4-GA-MP conjugates. This scheme yields a lower conjugation ratio of MP, presumably because of lower reactivity and steric hindrance for the steroid at the crowded dendrimer periphery. In scheme B, this steric hindrance was overcome by first preparing the MP-GA conjugate, which was then coupled to the PAMAM-G4-OH dendrimer. The H-1 NMR spectrum of the conjugate from scheme B indicates a conjugation of 12 molecules of MP with the dendrimer, corresponding to a payload of 32 wt %. In addition, conjugates were further fluorescent-labeled with fluoroisothiocynate (FITC) to evaluate the dynamics of cellular entry. Flow cytometry and UV/visible spectroscopic analysis showed that the conjugate is rapidly taken up inside the cell. Fluorescence and confocal microscopy images on A549 human lung epithelial carcinoma cells treated with conjugates show that the conjugate is mostly localized in cytosol. MP-GA-dendrimer conjugate showed comparable pharmacological activity to free MP, as measured by inhibition of prostaglandin secretion. These conjugates can potentially be further conjugated with a targeting moiety to deliver the drugs to specific cells in vivo.