CReST, Chemical Engineering Division, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
Langmuir. 2010 Apr 20;26(8):5772-81. doi: 10.1021/la903595x.
Polypeptide polymer-grafted silica nanoparticles are of considerable interest because the ordered secondary structure of the polypeptide grafts imparts novel functional properties onto the nanoparticle composite. The synthesis of poly-L-lysine-grafted silica nanoparticles would be of particular interest because the high density of cationic charges on the surface could lead to many applications such as gene delivery and antimicrobial agents. In this work, we have developed a "grafting-to" approach using a combination of NCA polymerization and "click chemistry" to synthesize poly-L-lysine-grafted silica nanoparticles with a high graft density of 1 chain/nm(2). The covalent attachment of poly-L-lysine to silica nanoparticles (PLL-silica) was confirmed using a variety of techniques such as (13)C CP MAS NMR, TGA, and IR. This methodology was then extended to graft poly-L-lysine-b-poly-L-leucine copolymer (PLL-b-PLLeu-silica) and poly-L-benzylglutamate (PLBG-silica) onto silica nanoparticles. All of these polypeptide-grafted nanoparticles show interesting aggregation properties in solution. The efficacy of PLL-silica and PLL-b-PLLeu-silica as antimicrobial agents was tested on both gram-negative E. coli and gram-positive Bacillus subtilis.
多肽聚合物接枝二氧化硅纳米粒子具有相当大的研究兴趣，因为多肽接枝的有序二级结构赋予纳米粒子复合材料新颖的功能特性。聚-L-赖氨酸接枝二氧化硅纳米粒子的合成将特别有趣，因为表面上高密度的阳离子电荷可能导致许多应用，如基因传递和抗菌剂。在这项工作中，我们使用 NCA 聚合和“点击化学”的组合开发了一种“接枝到”方法，合成了具有 1 链/nm(2)高接枝密度的聚-L-赖氨酸接枝二氧化硅纳米粒子。通过各种技术（如(13)C CP MAS NMR、TGA 和 IR）证实了聚-L-赖氨酸与二氧化硅纳米粒子（PLL-二氧化硅）的共价键合。然后，该方法被扩展到将聚-L-赖氨酸-b-聚-L-亮氨酸共聚物（PLL-b-PLLeu-二氧化硅）和聚-L-苯丙氨酸（PLBG-二氧化硅）接枝到二氧化硅纳米粒子上。所有这些多肽接枝纳米粒子在溶液中都表现出有趣的聚集特性。测试了 PLL-二氧化硅和 PLL-b-PLLeu-二氧化硅作为抗菌剂对革兰氏阴性大肠杆菌和革兰氏阳性枯草芽孢杆菌的功效。
