生物谷報道：美國科學家的一項最新研究表明,，單壁碳納米管能夠嚴重破壞大腸桿菌（E. coli）等細菌的細胞壁,，從而將其殺滅,。相關(guān)論文發(fā)表在美國化學學會的《朗繆爾》（Langmuir）雜志上,。
在美國化學學會的一項預審中，該項研究被認為“首次找到了碳納米管具有強大抗菌活性的直接證據(jù),，將有助于解決細菌抗藥性這一日益突現(xiàn)的問題,。”
論文高級作者、美國耶魯大學化學和環(huán)境工程系主任Menachem Elimelech表示,，“我們開始這項研究是基于對納米管在水環(huán)境和食物鏈中潛在毒性的關(guān)注,。由于碳納米管只有人類頭發(fā)絲的千分之一粗細,，因此很容易進入細胞,。不過，科學家對納米管如何與人類和環(huán)境進行相互作用知之甚少,。”
在最新的研究中,，研究人員在有碳納米管存在的情況下培育實驗模型——大腸桿菌近一個小時。結(jié)果發(fā)現(xiàn)，只要病菌與單壁碳納米管直接接觸,，就會被徹底殺滅,。Elimelech推測，可能是長而細的碳納米管刺破了細胞,，從而產(chǎn)生傷害,。同時，研究排除了金屬毒性作祟的可能,，因為為了避免金屬污染,，單壁碳納米管的合成和凈化過程都十分嚴格。
Elimelech小組目前正在研究多壁碳納米管的毒性,，初步的結(jié)論是它比單壁碳納米管的毒性要弱,。此外，研究人員也致力于在更廣泛的細菌種類中進行類似實驗,，以期更好地理解碳納米管破壞細胞的機制,。（科學網(wǎng) 任霄鵬/編譯）
英文全文:
Langmuir, 23 (17), 8670 -8673, 2007. 10.1021/la701067r S0743-7463(70)01067-3
Web Release Date: July 21, 2007 Copyright © 2007 American Chemical Society
Single-Walled Carbon Nanotubes Exhibit Strong Antimicrobial Activity
Seoktae Kang, Mathieu Pinault, Lisa D. Pfefferle, and Menachem Elimelech*
Department of Chemical Engineering, Yale University, P.O. Box 208286, New Haven, Connecticut 06520-8286
Received April 12, 2007
In Final Form: June 12, 2007
Abstract:
We provide the first direct evidence that highly purified single-walled carbon nanotubes (SWNTs) exhibit strong antimicrobial activity. By using a pristine SWNT with a narrow diameter distribution, we demonstrate that cell membrane damage resulting from direct contact with SWNT aggregates is the likely mechanism leading to bacterial cell death. This finding may be useful in the application of SWNTs as building blocks for antimicrobial materials.
Carbon-based nanomaterials, such as fullerene and carbon nanotubes (CNTs), exhibit unique size- and structure-dependent optical, electronic, magnetic, thermal, chemical, and mechanical properties.1 As a result, it is not surprising that these nanomaterials have been considered for use in numerous applications, including the fabrication of superconductors, optical devices, sensors, energy storage devices, fuel cells, and catalysts.2 However, such extraordinary physical and chemical properties are accompanied by concerns about possible adverse effects of these materials on biological systems. In particular, applications that use single-walled carbon nanotubes (SWNTs) for biosensors,3 drug and vaccine delivery transporters,4,5 and novel biomaterials6 increase the potential for encounters between SWNTs and humans and the ecosystem. Future commercial development of nanotechnology may also lead to the discharge of SWNTs into the environment.
Information concerning the potential toxicity from exposure to SWNTs and their environmental impact is scarce, often debated,7 and focused on human cells.8-11 The toxicity of SWNTs to human cells has been observed to vary with SWNT functionalization and the concentration of the solubilizing agent (i.e., surfactants),12,13 as well as with SWNT physicochemical properties such as structure, diameter, cleanliness (e.g., % metal), and defect level.14 In these studies, however, commercial SWNTs were used, and characterization was not well defined. Furthermore, for these SWNTs, factors such as mean diameter, diameter distribution, metal content, and defect level cannot be independently varied because of limitations of the SWNT synthesis, cleaning, and separation processes. Commercial SWNTs have generally been treated with strong acids and contain on average 4.5-15% metal and other impurities.15 Only a handful of groups can produce SWNTs with a narrow diameter distribution.16
