sally208 2008-05-23 12:05
JACS：美首次发现金纳米粒子具有抗HIV潜在能力
[table=98%,#f8f9f4][tr][td]作者：尼特 来源：网易探索 发布时间：2008-5-23 9:35:41
[/td][/tr][tr][td][align=left][table=98%][tr][td][/td][/tr][tr][td][/td][/tr][tr][td]JACS：美首次发现金纳米粒子具有抗HIV潜在能力[/td][/tr][tr][td][/td][/tr][/table]
据美国探索频道报道，[size=2][color=red][b]美国北卡罗来纳州大学的科学家表示实验已经首次表明金纳米粒子具有抗艾滋病的潜在能力，能够复兴失败了的抗艾滋病病毒（HIV）药物的威力。[/b][/color][/size]
20世纪90年代，科学家测试了抗艾滋病病毒药物TAK779能成功阻止HIV与人类的白血球结合，但在使用的同时会产生严重的副作用，因此这种药物没能成为一种有效的治疗手段。科学家表示此药中的一种铵盐是导致严重副作用的主要原因，消除它就可以消除副作用，但也会失去抗HIV的能力，因为这会导致此药的有效分子不能和HIV病毒紧密结合。
为克服这一困难，如今科学家在消除此铵盐的情况下，他们通过将此药物和金纳米粒子结合起来，进行了有关的实验，实验证实这一结合不仅加大了此药物阻止HIV病毒感染实验室培育的白血球的能力，还消除了此药物的副作用。他们的实验还表明当每一个金纳米粒子平均装载12个药物分子时，其对抗HIV病毒的能力和先前的TAK779药物相当。这是首次表明金纳米粒子具有抗艾滋病的潜在能力。此研究成果发表在最近出版的《美国化学会会志》（[i]JACS[/i]）上。
负责此项研究的北卡罗来纳州大学的T•埃里克•鲍拉德说：“此技术如同维可牢尼龙搭扣。一个交互作用是弱的，但如果许多的交互作用聚在一起，它们就会产生强大的交互作用。”
在没有此铵盐的情况下，TAK779将会再次重新考虑作为一种对抗艾滋病的潜在治疗药物。没有参与此项研究的科学家表示，同一技术将最终用于不同疾病的治疗中。不过，研究人员目前只测试了TAK779/金纳米粒子的联体在培育细胞中的效果。在临床应用之前，它还需要更加广泛的测试。
研究人员表示他们下一步尝试把其它药物和金纳米粒子结合起来使用。比如将抗病毒药和葡萄糖与金纳米粒子结合起来，看它们是否能越过脑血管障碍，从而制造出大脑中的抗病毒药物，而这在之前是不可能做到的。
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科学网
nanost-admin 2008-05-24 00:19
作用机理值得重视研究。目前广泛应用的AG的抗菌和杀菌机理也还是不狠清楚的！
nanost-admin 2008-05-25 06:23
Failed HIV Drug Gets Second Chance with Addition of Gold Nanoparticles
[b][color=Blue]Researchers at North Carolina State University have discovered that adding tiny bits of gold to a failed HIV drug rekindle the drug's ability to stop the virus from invading the body's immune system.[/color][/b]
The addition of gold nanoparticles to a modified version of a drug designed in the 1990s to combat HIV - but discarded due to its harmful side effects - creates a compound that prevents the virus from gaining a cellular foothold, say Dr. Christian Melander, assistant professor of chemistry at NC State, and doctoral student T. Eric Ballard.
Their findings appear online in the Journal of the American Chemical Society.
The drug, a compound known as TAK-779, was originally found to bind to a specific location on human T-cells, which blocks the HIV virus' entry to the body's immune system. Unfortunately, the portion of the drug's molecule that made binding possible had unpleasant side effects. When that portion of the molecule - an ammonium salt - was removed, the drug lost its binding ability.
That's when the researchers turned to gold as the answer. The element is non-reactive in the human body, and would be the perfect "scaffold" to attach molecules of the drug to in the absence of the ammonium salt, holding the drug molecules together and concentrating their effect.
"The idea is that by attaching these individual molecules of the drug with a weak binding ability to the gold nanoparticle, you can magnify their ability to bind," Melander says.
The researchers' theory proved correct. They started with a modified version of TAK-779, which didn't include the harmful ammonium salt. After testing, they found that attaching 12 molecules of the modified drug (SDC-1721) to one nanoparticle of gold restored the drug's ability to prevent HIV infection in primary cultured patient cells. When only one molecule of the drug was attached to the gold nanoparticle, the compound was unable to prevent HIV infection, indicating that the multivalency of the drug was important for its activity.
"We've discovered a non-harmful way to improve the strength and efficacy of an important drug," Melander says. "There's no reason to think that this same process can't be used with similar effect on other existing drugs."
Source: North Carolina State University