Tesauro Diego, Accardo Antonella, Gianolio Eliana, Paduano Luigi, Teixeira José, Schillén Karin, Aime Silvio, Morelli Giancarlo
Department of Biological Sciences, CIRPeB University of Naples, Federico II and IBB CNR, Via Mezzocannone 16, Naples, Italy.
Chembiochem. 2007 May 25;8(8):950-5. doi: 10.1002/cbic.200700077.
The relaxivity behaviour and the structural characterization of new supramolecular aggregates (bilayer structures and micelles) obtained by combining two different amphiphilic monomers are reported. One monomer, (C18)(2)DTPAGlu-Gd, contains a very stable gadolinium complex, and the other, DSPE-PEG(2000)-CCK8, contains the bioactive CCK8 peptide. Samples that contained only DSPE-PEG(2000)-CCK8, or up to 50 % (C18)(2)DTPAGlu-Gd, aggregated as double-layer structures (lamellar aggregates) with a thickness of approximately 80-100 A, as evaluated by SANS measurement and Cryo-TEM imaging. A transition to micelle formation was observed when the amount of (C18)(2)DTPAGlu-Gd in the aggregate was increased. These were rod-like micelles approximately 40 A in radius and >200 A in length. The proton relaxivities for both lamellar aggregates and rod-like micelles were the same (17.2 mM(-1) s(-1)), although the values were the results of different combinations of local and global contributions. The in vitro target selectivity of aggregates that contained the CCK-8 peptide was demonstrated by using nuclear medicine techniques.
报道了通过结合两种不同的两亲性单体获得的新型超分子聚集体（双层结构和胶束）的弛豫行为和结构表征。一种单体（C18）2DTPAGlu-Gd包含一个非常稳定的钆配合物，另一种单体DSPE-PEG(2000)-CCK8包含生物活性CCK8肽。仅含有DSPE-PEG(2000)-CCK8或高达50%（C18）2DTPAGlu-Gd的样品，通过小角中子散射测量和冷冻透射电子显微镜成像评估，聚集成厚度约为80-100埃的双层结构（层状聚集体）。当聚集体中（C18）2DTPAGlu-Gd的量增加时，观察到向胶束形成的转变。这些是半径约为40埃、长度大于200埃的棒状胶束。层状聚集体和棒状胶束的质子弛豫率相同（17.2 mM-1 s-1），尽管这些值是局部和全局贡献不同组合的结果。通过使用核医学技术证明了含有CCK-8肽的聚集体的体外靶向选择性。
