De Santis Serena, Novelli Federica, Sciubba Fabio, Casciardi Stefano, Sennato Simona, Morosetti Stefano, Scipioni Anita, Masci Giancarlo
Dipartimento di Chimica, Sapienza Università di Roma, P.le A. Moro, 5, I-00185 Rome, Italy.
National Institute for Insurance against Accidents at Work (INAIL Research), Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Rome, Italy.
J Colloid Interface Sci. 2019 Jul 1;547:256-266. doi: 10.1016/j.jcis.2019.03.093. Epub 2019 Mar 29.
Preparation and characterization of a pH and thermosensitive linear l,d-octapeptide-poly(dimethylamino ethyl methacrylate) ((l-Val-d-Val)-PDMAEMA) conjugate is reported. The hydrophobic uncharged linear (l-Val-d-Val) octapeptide was designed to self-assemble in nanotubes by exploiting the tubular self-assembling properties of linear peptides with regularly alternating enantiomeric sequences. pH and thermosensitive PDMAEMA was obtained by atom transfer radical polymerization (ATRP). The conjugate was prepared by click-chemistry on the solid phase synthetized peptide. Because of the strong interactions between the peptide moieties, long single channel nanotubes (0.2-1.5 μm) are formed also at acidic pH with the fully charged polymer. At 25 °C and basic pH the size of the nanotubes did not change significantly. In basic conditions and temperature above the PDMAEMA lower critical solution temperature (LCST) a significant increase of the length of the nanotubes up to several micrometers is observed. The size is retained for several days after cooling back to room temperature. Sonication significantly reduces the nanotube length (0.2-0.5 μm) forming low polydisperse nanotubes. The elongation of the nanotubes is fully reversible by restoring acidic pH. This is the first example, to our knowledge, of thermosensitive peptide-polymer single channel nanotubes with length that can be varied from hundreds of nanometers to several micrometers.
报道了一种pH和温度敏感的线性L，D - 八肽 - 聚（甲基丙烯酸二甲氨基乙酯）（（L - Val - D - Val）-PDMAEMA）共轭物的制备与表征。疏水性不带电荷的线性（L - Val - D - Val）八肽通过利用具有规则交替对映体序列的线性肽的管状自组装特性设计成在纳米管中自组装。pH和温度敏感的PDMAEMA通过原子转移自由基聚合（ATRP）获得。共轭物通过在固相合成肽上进行点击化学制备。由于肽部分之间的强相互作用，在酸性pH下与完全带电的聚合物也形成长的单通道纳米管（0.2 - 1.5μm）。在25°C和碱性pH下，纳米管的尺寸没有显著变化。在碱性条件下且温度高于PDMAEMA的低临界溶液温度（LCST）时，观察到纳米管长度显著增加至几微米。冷却回到室温后，尺寸保持几天。超声处理显著降低纳米管长度（0.2 - 0.5μm），形成低多分散性的纳米管。通过恢复酸性pH，纳米管的伸长是完全可逆的。据我们所知，这是具有可从数百纳米变化到几微米长度的温度敏感肽 - 聚合物单通道纳米管的第一个例子。
