New supercharged scalpel takes on cancer
新適癌超動力手術刀。
When a surgeon removes a tumor, some cancer cells may get left behind, threaten-ing to seed another malignant growth. Researchers have just begun the first clinical trial of a new anticancer tool that they hope will kill these stubborn cells: a plasma scalpel.
當外科醫生切除腫瘤塊時，一些癌細胞可能會被遺忘，這無異於會對身體造成下一次惡性生長的隱患。研究人員們已經開始在臨牀試驗中使用新的抗癌工具-‘等離子手術刀’用於幫助他們殺死頑固的癌細胞。
The pen-size scalpel emits a small jet of helium whose charged particles glow with a vivid lilac hue. An electrode at the scalpel’s tip splits some of the helium atoms into a plasma soup of positive ions and electrons.
這種筆式手術刀發射一小股的氦流，它的帶電粒子會發出鮮豔的淡紫色亮光，手術刀尖端的電極會將一些氦原子分離成陽離子和帶電粒子的等離子體。
Unlike in the sun’s blazing plasma, the scalpel’s ions are relatively slowmoving— so the jet feels like a cool breeze to the touch. But its fast electrons are packed with energy and can convert atmospheric oxygen and nitrogen into reactive forms, including superoxide, nitric oxide and atomic oxygen. These substances can interrupt key metabolic processes and hamper cell reproduction, and researchers have found that cancer cells are much more vulnerable to such effects than healthy cells are. The scalpel can be used on a tumor site for just a few minutes during surgery, says Jerome Canady, a surgeon in Washington, D.C., and part of the team that developed the tool. “We just spray that area with plasma to kill any microscopic tumors,” he says.
與太陽般熱烈的等離子不同，這種手術刀的離子移動是相對緩慢的，所以它的感覺像微風一般清爽。但是當它的電子快速充滿能量後，可以將空氣中的氧氣和氮氣轉換爲包含過氧化物，一氧化氮和原子氧的活躍形態。這些物質可以中斷關鍵的代謝進程和阻礙細胞繁殖，並且研究人員發現了癌細胞比健康細胞更容易受這兩種方式的影響。一個來自華盛頓的外科醫生Jerome Canady和開發該工具的團隊成員說：“等離子手術刀只需要短暫幾分鐘即可用於完成的腫瘤塊手術的過程中。我們只需要將等離子噴射至病竈區域就可以殺死所有的小腫瘤快”。
Cold plasma is already used to treat infections and sterilize wounds, and more energetic plasma can neatly cut or cauter ize tissue. Turning it against cancer has long been a goal, and the new trial is a major milestone, says Mounir Laroussi, who studies the biological effects of cold plasma at Old Dominion University. “I think this is huge,” he says.
Mounir Laroussi說道：“低溫等離子體可以用於治療感染和創口消毒，更多強力的等離子可以整體的切割或燒灼組織。用它來對抗癌症是一個長遠的目標，並且這次新的嘗試將會是一個里程碑的進展，我在美國弗吉尼亞州大學研究了低溫等離子體的生物效應，所獲甚多”。
In the past few years doctors have used plasma scalpels on three cancer patients on a “compassionate use” basis, after all other reatment options had failed. The plasma successfully killed residual cancer cells in these people, Canady says, but a full clinical trial will provide vital data about safety and longerterm effects. As Scientific American went to press, Canady and his colleagues were due to perform the first surgery of their trial in late October 2019. They aim to use the plasma scalpel on 20 patients with latestage solid cancers, including those affecting the pancreas, ovary or breast.
Canady說，在過去幾年中，醫生在3個病人上在其他所有治療方式均宣告失敗時，依照“同情使用”（ext: 在美國，這種方法是在FDA批准之前爲沒有其他治療選擇的重病患者提供實驗藥物或療法的方法)的方式使用了等離子手術刀。等離子手術刀成功的殺死了身體內殘留的癌細胞。但是需要一個完整的試驗來對臨牀試驗的安全性和長期影響提供至關重要的數據。在《Scientific American》出版時，Canady和他的同事在2019年10月底進行他們第一次試驗的手術。他們的目標是使用等離子手術刀治療的20名病人和癌症晚期病人，這些病人包括了癌症對胰腺，卵巢，胸部的影響的患者。
Laroussi says it took more than a decade of laboratory work on cell cultures and animals to prepare the plasma scalpel for the clinic. The process involved identifying the chemicals it generates, measuring their penetration into tissue and understanding how the disruption of cancer cells works. “You also have to stay below a certain dose—otherwise you kill both cancer cells and healthy cells,” he says. Laroussi hopes the trial will show that the device can be fine-tuned to take out its cancerous quarry without causing unwanted damage. —Mark Peplow
Laroussi 說：它在實驗室爲細胞培養和動物實驗做了10多年的工作，時刻準備着等離子手術刀在臨牀上的應用。這個過程包含確認術後產生的化學遺留物，測量它們對組織的滲透以及和癌細胞是如何分裂的原理。因爲等離子手術刀在殺死癌細胞的同時還會殺死你正常的細胞，所以這種方式對身體的危害還必須保持在一定劑量下。Laroussi希望這次試驗能證明等離子手術刀對癌症的功效是可以提高的，在達到治癒效果的同時儘量減少對正常身體組織不必要的傷害。—Mark Peplow