Dendrimers Terminated with Dichlorotriazine Groups Provide a Route to Compositional Diversity
摘要:
Triazine dendrimers terminated with either four or eight dichlorotriazines can be prepared in high yields by reacting an amine-terminated dendrimer with cyanuric chloride. These materials exist as white powders and are stable to storage at room temperature. Sequential nucleophilic aromatic substitution with two different amine nucleophiles yields compounds that display the desired compositional diversity. Reaction conditions for the substitution were developed using a model dichlorotriazine with amine nucleophiles at -20,0, and 25 degrees C. Selective substitution is favored at lower temperatures and with more nucleophilic amine groups.
Design, Synthesis and Biological Assessment of a Triazine Dendrimer with Approximately 16 Paclitaxel Groups and 8 PEG Groups
作者:Changsuk Lee、Su-Tang Lo、Jongdoo Lim、Viviana C. P. da Costa、Saleh Ramezani、Orhan K. Öz、Giovanni M. Pavan、Onofrio Annunziata、Xiankai Sun、Eric E. Simanek
DOI:10.1021/mp400290u
日期:2013.12.2
The synthesis and characterization of a generation three triazine dendrimer that displays a phenolic group at the core for labeling, up to eight 5 kDa PEG chains for solubility, and 16 paclitaxel groups is described. Three different diamine linkers-dipiperidine trismethylene, piperazine, and aminomethylpiperidine-were used within the dendrimer. To generate the desired stoichiometric ratio of 8 PEG chains to 16 paclitaxel groups, a monochlorotriazine was prepared with two paclitaxel groups attached through their 2'-hydroxyls using a linker containing a labile disulfide. This monochlorotriazine was linked to a dichlorotriazine with aminomethylpiperidine. The resulting dichlorotriazine bearing two paclitaxel groups could be reacted with the eight amines of the dendrimer. NMR and MALDI-TOF confirm successful reaction. The eight monochlorotriazines of the resulting material are used as the site for PEGylation affording the desired 2:1 stoichiometry. The target and intermediates were amenable to characterization by H-1 and C-13 NMR, and mass spectrometry. Analysis revealed that 16 paclitaxel groups were installed along with 5-8 PEG chains. The final construct is 63% PEG, 22% paclitaxel, and 15% triazine dendrimer. Consistent with previous efforts and computational models, 5 kDa PEG groups were essential for making the target water-soluble. Molecular dynamics simulations showed a high degree of hydration of the core, and a radius of gyration of 2.8 +/- 0.2 nm. The hydrodynamic radius of the target was found to be 15.8 nm by dynamic light scattering, an observation indicative of aggregation. Drug release studies performed in plasma showed slow and identical release in mouse and rat plasma (8%, respectively). SPECT/CT imaging was used to follow biodistribution and tumor uptake. Using a two component model, the elimination and distribution half-lives were 2.65 h and 38.2 h, respectively. Compared with previous constructs, this dendrimer persists in the vasculature longer (17.33 +/- 0.88% ID/g at 48 h postinjection), and showed higher tumor uptake. Low levels of dendrimer were observed in lung, liver, and spleen (similar to 6% ID/g). Tumor saturation studies of small prostate cancer tumors (PC3) suggest that saturation occurs at a dose between 23.2 mg/kg and 70.9 mg/kg.
Dendrimers Terminated with Dichlorotriazine Groups Provide a Route to Compositional Diversity
作者:Subrata Patra、Brittany Kozura、Adela Y.-T. Huang、Alan E. Enciso、Xiankai Sun、Jer-Tsong Hsieh、Chai-Lin Kao、Hui-Ting Chen、Eric E. Simanek
DOI:10.1021/ol400811h
日期:2013.8.2
Triazine dendrimers terminated with either four or eight dichlorotriazines can be prepared in high yields by reacting an amine-terminated dendrimer with cyanuric chloride. These materials exist as white powders and are stable to storage at room temperature. Sequential nucleophilic aromatic substitution with two different amine nucleophiles yields compounds that display the desired compositional diversity. Reaction conditions for the substitution were developed using a model dichlorotriazine with amine nucleophiles at -20,0, and 25 degrees C. Selective substitution is favored at lower temperatures and with more nucleophilic amine groups.
Influence of linker groups on the solubility of triazine dendrimers
作者:Alan E. Enciso、Matteo Garzoni、Giovanni M. Pavan、Eric E. Simanek
DOI:10.1039/c4nj00917g
日期:——
The choice of linking diamine has profound influence on the solubility of triazine dendrimers.