18/11/10

健康的纳米技术:事实和数字

Nanotech can ensure targeted-drug delivery to specific areas in the body — with drugs formulated to permeate cell membranes better, reducing the required dose. Copyright: RutgersUniv

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发展中国家可以使用纳米技术来改善健康吗?Priya Shettylooks at nanomedicine’s promise.

纳米技术(非常小的科学)具有巨大的医疗保健潜力,从更有效地提供药物,更迅速,更灵敏地诊断疾病,并通过气溶胶和斑块传递疫苗。

纳米技术是分子或亚原子水平的材料科学。它涉及对小于100纳米的颗粒操纵(一个纳米分数为十亿米),并且该技术涉及在该尺寸内的开发材料或设备 - 人眼看不见,并且通常比人毛的宽度薄数百倍。材料的物理和化学降低到纳米级时,材料的化学完全不同。它们具有不同的优势,电导率和反应性,并且利用这可能会彻底改变医学。

例如,现代医学的主要挑战是,人体不会吸收给患者的整个药物剂量。使用纳米技术,科学家可以确保以更精确的精度将药物递送到体内的特定区域,并且可以配制药物,从而使活性成分更好地渗透到细胞膜,从而减少所需的剂量(请参阅面板1)。

Rich countries are investing heavily in nanotechnology for health. The first generation of cancer drugs delivered via nanoparticles, for example, has already been approved by the US Food and Drug Administration (FDA).

However, it is still early days for nanotechnology in healthcare and whether it will be of value to resource-poor countries is still hotly debated. Critics argue that when millions of people in countries like India or those in Sub-Saharan Africa are dying because of a lack of access to even basic healthcare, investing in cutting-edge technologies is a ludicrous waste of money. [1]

专家们担心纳米颗粒对人类健康和环境的毒性尚未得到充分的研究。beplay足球体育的微博例如,英国皇家学会和皇家工程学院2004年的一份报告建议将纳米颗粒和纳米管(圆柱形碳分子比普通碳分子更好的导体分子)视为有害废物。[2]

许多新兴经济体,例如巴西,中国,印度,伊朗,马来西亚,墨西哥,新加坡和南非,都雄心勃勃的研究与开发计划(R&D)纳米技术计划。他们的政府需要平衡短期健康需求与长期技术投资。

然而,尽管贫困国家有持续的责任来加强医疗保健系统并提供更广泛的医学机会,但从长远来看,纳米技术可以通过使诊断和治疗更有效地挽救生命。

A group of scientists who have mapped out the uses of nanotechnology and the needs of global health argue that nanomedicine is relevant for the developing world. They surveyed researchers worldwide and concluded that nanotechnology could greatly contribute to meeting the Millennium Development Goals for health. Specifically, the goals to reduce child mortality, improve maternal mortality and combat HIV/AIDS, malaria and other diseases. [3]

诊断和筛查

There is an urgent need in the developing world for better disease diagnosis, and nanotechnology offers a multitude of options for detecting disease (see panel 1 on uses for nanotechnology).

荧光量子点可以通过靶向血细胞的内膜来改善疟疾诊断。

谁/TDR/Andy Crump

一种方法是使用量子点 - 纳米化的半导体,可以用作生物传感器找到疾病并可以制成荧光。有时被称为纳米晶体,量子点比传统有机染料具有显着的优势,因为它们的发光可以调整为各种频率,并且它们在体内的降解速度较慢。荧光量子点可以标记为靶向癌细胞或感染结核病(TB)或HIV的细胞的抗体(请参阅纳米技术和结核病的第3块)。[4,5]

Fluorescent quantum dots could also be used to diagnose malaria by making them target the protein that forms a mesh in the blood cell’s inner membrane. The shape of this protein network changes when cells are infected with malaria, so scientists are able to spot malaria infection from the shape produced by the dots. [6]

Similarly, carbon nanotubes, and other nanoparticles such as nanowires, have been used as biosensors to detect diseases such as HIV and cancer. Cancer biosensors can be made, for instance, by attaching nucleic acid probes to the ends of nanowires. These probes are specifically designed to bond to biomarkers that indicate cancer such as mutated RNA. When mutated RNA in a sample interacts with the probes, electric currents are induced along the nanowire, which is detected by the silicon chip in which the biosensor is embedded. [7]

药物输送

Nanotechnology could also revolutionise drug delivery by overcoming challenges such as how to sustain the release of drugs in the body and improving bioavailability — the amount of active ingredient per dose.

Some drugs can now be delivered through ‘nanovehicles’. For example liposomes, which can deliver the drug payload by fusing with cell membranes, have been used to enscapsulate HIV drugs such as stavudine and zidovudine in vehicles ranging from 120 to 200 nanometres in size. [7] Since both these drugs have short half-lives, the liposome coating could potentially make them active for longer periods.

Other nanodrug delivery systems include using fullerene ‘buckyball’ cages, [8] and branched nanomolecules called dendrimers (see panel).

面板1.纳米技术在健康中的用途

There are several developments in nanotechnology that can help improve health in developing countries.

疾病诊断和筛查

  • Nanolitre systems (known as lab-on-a-chip): devices that automate a biological process using fluids at the nanolitre scale.
  • 量子点:可以用作发现疾病的生物传感器的纳米化半导体。因为它们荧光,它们可用于标记患病的细胞。
  • 磁nanoparticles: used as nanosensors
  • 纳米传感器阵列:碳纳米管的网格
  • 抗体树枝状聚合物缀合物:带有抗体末端的分支纳米分子以诊断HIV和癌症
  • 碳纳米管和平坦的碳纤维,称为纳米带或纳米线(通常由黄金制成)作为疾病诊断的纳米传感器,因为它们与表明癌症(例如突变RNA)的生物标志物结合在一起
  • Nanoparticles as medical image enhancers: medical imaging relies on looking for contrasts in the way light is scattered in healthy tissue compared with diseased tissue. The sharper this contrast, the more accurate the diagnosis. Nanoparticles are able to give medical imaging techniques a sharper resolution, making it easier to identify disease.

药物输送systems

系统的选择取决于它们与药物结合的方式和药物治疗的类型。

  • Nanocapsules: these are pods that encapsulate drugs, which ensures the drugs are released more slowly and steadily in the body
  • 脂质体:由脂质双层组成的人造囊泡,使它们可以与膜融合并轻松穿透膜。这些已用于治疗癌症,真菌感染,丙型肝炎和流感。
  • 树枝状聚合物:树状合成纳米分子,在分支的尖端中携带药物。
  • Buckyballs: spherical nanoparticles can carry more than one drug at a time. They are useful in the treatment of diseases such as cancer and other diseases where monotherapy can lead to drug resistance
  • Nanobiomagnets which carry drugs, for cancer for instance, into the body and are held at the target site by an external magnet. The purpose of this is to concentrate the drug at the tumour site for long enough for it to be absorbed.
  • 带有纳米大小的毛孔的阿atapulgite粘土,非常适合从水中滤除有害细菌
  • 纳米技术也能提供替代品jectable vaccines if the inactive virus is bound up with nanoparticles to increase the immune response.

Health monitoring

纳米管和纳米颗粒可用作葡萄糖,二氧化碳和胆固醇传感器,以及用于稳态的原位监测,该过程使人体保持代谢平衡。


在发达国家中,癌症是针对纳米医学治疗的疾病列表的头号(请参阅《癌症》第2次)。根据世卫组织的说法,在发展中国家中,癌症患病率正在迅速上升,占所有癌症死亡的70%。在发展中国家中,在与艾滋病毒和结核病等传染病的斗争中还探讨了纳米技术的使用。

Panel 2: Could nanotech help cure cancer?

Nanotechnology advances have been heavily focused on cancer, mainly on diagnosis and drug delivery.

通过聚合物涂覆的纳米颗粒携带的药物已被用来用化学疗法紫杉醇抑制细胞分裂和隆尼胺的化学疗法来治疗多药耐药性乳腺癌和卵巢癌,从而抑制了癌细胞中能量代谢。纳米颗粒旨在靶向表皮生长因子受体,该因子在肿瘤细胞中过表达。[9]

Detecting cancer early can make a significant difference to the survival rate. Using magnetic nanoparticles in a miniature magnetic resonance sensor is so sensitive, scientists can detect as few as two cancer cells in one microlitre of a biosample, radically increasing early detection. [10]

斯坦福大学的科学家在美国圣ates have used nanotechnology to devise a highly specific method of killing cancerous cells. They inserted carbon nanotubes into cancer cells and then exposed the tissue to near-infrared laser light, heating up the nanotubes and killing the cancer cells while leaving the healthy cells intact. [11]


Panel 3: Tuberculosis and nanotechnology

The Central Scientific Instruments Organisation of India has designed a nanotechnology-based TB diagnostic kit, currently undergoing clinical trials. This would cut both the cost and time required for TB tests, and also require a smaller amount of blood for testing.

纳米技术也被用来更有效地治疗结核。现有的结核病治疗需要在几个月内提供复杂的药物方案。许多患者无法正确服用药物或无法完成课程。基于纳米技术的药物制剂降解更慢,从而使更多的活性成分递送,因此需要更少的剂量。

The drugs are encapsulated in biodegradable polymers such as liposomes and microspheres, which ensure sustained delivery of the medicine. Nanoparticles of polylactide co-glycolide, a polymer often used to deliver drugs since it degrades well and doesn’t cause an immune reaction,have been successfully tested as drug carriers for TB由美国哈佛大学的小组,印度的研究生教育研究所以及南非科学与工业研究委员会。

纳米颗粒也可能是输送气溶胶结核病疫苗的基础。无针,因此不需要训练有素的人员对其进行管理,该疫苗在室温下是稳定的 - 在缺乏可靠的冷链的农村地区很重要。


Vaccines

Nanotechnology could herald a new era in immunisation by providing alternatives to injectable vaccines for diseases that affect the poor. Injectable vaccines need to be administered by healthcare professionals, who may be scarce in developing countries, particularly in rural areas. Vaccines also need reliable refrigeration along the delivery chain. Scientists are working on an aerosol TB vaccine (see panel 3). They are also investigating a nanotechnology-based skin patch against West Nile Virus and Chikungunya virus. [12]

纳米技术可以为依赖医疗保健专业人员管理的可注射疫苗提供替代品

谁/TDR/Andy Crump

Injectable vaccines can be useful if the inactive virus is bound up with nanoparticles to increase the immune response. This method is being used to devise a vaccine against pandemic influenza. [13]

Leaders of the pack

China is by far top of the leader board for nanotechnology research among developing countries, registering the most nanotechnology patents. It has had a national nanotechnology programme since the early 1990s, and a huge number of new nanotechnology companies are set up every year. [14]

India is also taking nanotechnology seriously, with over 30 institutions involved in research. South-East Asian countries are especially active, with Malaysia, the Philippines, Thailand and Vietnam all engaged in nanotechnology research.

同时在非洲South Africa has both its private and public sector working on nanotechnology R&D。Brazil, which is leading nanotechnology research in Latin America, has partnered with South Africa and India to promote South–South collaboration through the IBSA Nanotechnology Initiative.

许多其他发展中国家希望追赶。2005年对全球纳米技术研究活动归类为国家活动或资金的调查(暗示着明确的国家战略或政府资金),至少有一个或研究小组从事纳米技术研究,或者让政府表示有兴趣追求纳米技术(请参阅表1,改编自[14])。

纳米技术是一门昂贵的科学,但是在国家之间建立研究所的成本似乎很大。例如,墨西哥和越南表示,建立纳米技术学院的费用约为500万美元,但哥斯达黎加表示,这样做的价格不到50万美元。[14]

Least developed

发展

过渡

National activity or funding

Argentina; Armenia; Brazil; Chile; China; Cost Rica; Egypt; Georgia; India; Iran; Mexico; Malaysia; Philippines; Serbia & Montenegro; South Africa, Thailand, Turkey; Uruguay; Vietnam

Belarus; Bulgaria; Cyprus; Czech Republic; Estonia; Hong Kong; Hungary; Israel; Latvia; Lithuania; Poland, Romania; Russian Federation; Singapore; Slovak Republic; Slovenia; South Korea; Ukraine

个人或小组研究

孟加拉国

Botswana; Columbia; Croatia; Cuba; Indonesia; Jordan; Kazakhstan; Moldova; Pakistan; Uzbekistan; Venezuela

澳门(中国);马耳他;阿拉伯联合酋长国

国家利益

Afghanistan; Senegal; Tanzania

阿尔巴尼亚;波斯尼亚和黑塞哥维那(简称:波黑;厄瓜多尔;加纳;肯尼亚;黎巴嫩;马其顿;斯里兰卡;斯威士兰;津巴布韦

Brunei Darussalam

Table 1: Nanotechnology league table

公众接受

What is technically possible and what is ethically appropriate is a matter of heated debate. In developing nations, nanomedicine evokes similar ethical issues to genetically modified foods. When people are desperately in need of food or medicine does it matter through what route it arrives? And whether illiterate or uneducated populations can be adequately involved in debates about the effects of these new technologies on society? [1]. The invisible nature of nanotechnology makes it easier to ‘hide’ nanotech products, and to invade privacy or carry out procedures that require consent, without the patient’s knowledge. This may be particularly pertinent with regard to clinical trials of nanodrugs carried out in developing countries.

发展中国家政府将需要谨慎行事。确保道德临床试验的能力在发达国家通常很差,并基于纳米技术引入健康产品可能需要缺乏的专业知识[2]。与其他健康技术一样,纳米技术在本质上没有任何好处或坏事。这将取决于它的使用方式。

In the field of health, advances in nanotechnology are combined with other technologies, including information technology and biotechnology, increasing nanotechnology’s potential to ‘displace’ health measures and systems where regulation has been worked out over many years. One example is the development of computer-controlled molecular tools that may not require the direct intervention of a medical practitioner. Or, nanosensors that measure and store medical information about an individual where issues might arise over the storage, access and use of such information.

Even in the developed world the study of legal, ethical, environmental and equity issues are lagging behind scientific advances in nanotechnology for health. Nanotechnology may not be as advanced in the developing world as in countries like the United Kingdom or the United States, but it’s only a matter of time before China and India catch up. Developing nations should not wait until the technology is on their doorstep before figuring out its ethical and societal implications.

本文是关注点的一部分纳米技术的健康

参考

[1] Court E.查尔斯王子等人会减少发展中国家在纳米技术方面的机会吗?(2004)Accessed 23 October 2010.

[2]The Royal Society and Royal Academy of Engineering纳米科学和纳米技术:机会和不确定性(2004)

[3] Salamanca-Buentello,F。纳米技术与发展中国家PLoS Medicinedoi:10.1371/journal.pmed.0020097 (2005)

[4] Maclurcan, D.C.Nanotechnology and Developing Countries Part 1: What Possibilities?Online Journal of Nanotechnology doi:10.2240/azojono0103 (2005)

[5] Mathuria,J.P。纳米颗粒在结核病诊断,治疗和预防中:对未来的希望。Digest Journal of Nanomaterials and Biostructures4,309-312(2009)

[6]Tokumasu, F通过使用量子点,通过自相关分析测定的恶性疟原虫感染的AA和CC红细胞中的Band 3修饰Journal of Cell Sciencedoi:10.1242/jcs.01662(2005)

[7] Mamo, T.新兴纳米技术方法用于HIV/AIDS治疗和预防纳米医学5,269-285(2010)

[8] Partha,R。Amphielic c的自助集60富勒烯衍生物进入纳米级超分子结构Journal of Nanobiotechnologydoi:10.1186/1477-3155-5-6 (2007)

[9]Milane,L.JDevelopment of EGFR-Targeted Polymer Blend Nanocarriers for Paclitaxel/Lonidamine Delivery to Treat Multi-Drug Resistance in Human Breast and Ovarian Tumor Cells分子药理学doi: 10.1021/mp1002653(2010年)[EPUB在印刷前]

[10]Lee, H。,,Rapid detection and profiling of cancer cells in fine-needle aspiratesProceedings of the National Academy of Sciencesdoi:106(30):12459-64(2009)

[11]坎姆,北卡罗来纳州。,,Carbon nanotubes as multifunctional biological transporters and near-infrared agents for selective cancer cell destructionProceedings of the National Academy of Sciencesdoi: 102(33):11600-5 (2009)

[12]PROW,T.WNanopatch-Targeted Skin Vaccination against West Nile Virus and Chikungunya Virus in MiceSmall6,1776-84(2010)

[13]Huang, M.H含有灭活流感病毒和CpG寡脱氧核苷酸的乳化纳米颗粒对小鼠的宿主免疫反应有严重影响PLOS ONEdoi:10.1371/journal.pone.0012279 (2010)

[14] Maclurcan,D.C。Nanotechnology and Developing Countries Part 1: What Realities?Online Journal of Nanotechnology doi:10.2240/azojono0104(2005)