〔編譯張沛元／綜合報導〕美國科學家已成功在實驗室中培養出人造迷你肝臟，日後可望造福有換肝需要的病患，以及用來檢驗實驗性新藥的安全。這項新研究30日發表於在美國波士頓召開的美國肝病研究協會年會。
透過把未成熟的人類肝臟細胞「播種」到動物肝臟的支架上進行培育，研究人員成功在實驗室中創造出核桃大小的迷你人造肝臟。該研究計畫主任、美國北卡羅來納州維克森林再生醫學研究所副教授索克說，他們對該研究呈現的可能性深感興奮，但也強調目前仍處於研究初步階段；在人造肝真正能造福病患之前，勢必還得克服許多技術障礙，包括得同時製造大量人造肝臟，以及確定這些人造肝臟安全無虞。
索克的同僚貝皮斯塔則表示，他們希望這些人造肝臟一旦移植到人體後，仍能持續發展以及維持正常功能。
研究人員解釋，他們利用一種溫和洗滌劑，去除掉雪貂肝臟上的細胞，使之只剩下膠原蛋白支架與血管；接著將未成熟的人類肝臟細胞「播種」到支架上。雪貂肝臟支架隨著這些細胞成長提供塑形與結構，至於血管則連接到生物反應器，以便提供氧氣、養分與帶走廢物。研究人員表示，人造肝臟在被放到生物反應器內培育一週後開始生長，而且功能與正常的人類肝臟無異。
此一技術若要能真正造福病患，至少還要5年，甚至更久。研究人員表示，接下來的步驟是觀察這些人造肝臟被移植回雪貂體內後，能否持續維持其功能，屆時才能考慮這種人造肝臟能否用於人類。美國波士頓的麻薩諸塞州綜合醫院的科學家，今年稍早也曾利用類似的動物支架技術，成功培育出迷你老鼠肝臟，並將之移植到活鼠內。接受移植的老鼠存活了數小時。
圖為科學家將動物肝臟去除細胞(左圖)，剩下膠原蛋白的骨架(中間)，再經由血管植入人類未成熟的肝臟細胞(右圖)
  
去細胞肝臟(decellularized liver) 膠原蛋白骨架(collagen scaffold) 再生肝臟(recellularized liver)
Scientists grow miniature human livers in the lab for the first time
A team of medical researchers have engineered the first artificial, miniature liver that functions similar to a human liver.
The results were presented by a team from Wake Forest University Baptist Medical Center at a conference in Boston.
The researchers were able to produce the human liver by using stem cells. The stem cells, nurtured with a mixture of nutrients and oxygen, separated into immature liver cells and endothelial cells, a new lining for the blood vessels. In a process called decellularization, the researchers stripped off all the cells from the existing organ by treating it with a mild detergent, leaving only the collagen “skeleton” or support structure. Then, the original cells were replaced with two types of human cells: progenitors, which are immature liver cells, and endothelial cells, which line blood vessels.
The livers were grown from human liver cells and are 1 inch in diameter and weigh approximately 20 ounces. For the liver to perform properly in humans, an engineered liver would have to weigh at least 1 pound, the team noted.
“We are excited about the possibilities this research represents, but must stress that we’re at an early stage and many technical hurdles must be overcome before it could benefit patients,” said the project director, Associate Professor Shay Soker from the Wake Forest Institute for Regenerative Medicine in North Carolina.
The researchers hope to grow functioning human livers one day. However, it will take this new technology at least five years to move from the laboratory to hospitals. The technology opens up the prospect of growing other replacement organs, including kidneys or pancreases, for patients who are able to donate stem cells.
Posted by 幹細胞達人 at 痞客邦 PIXNET
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发表于 2010-11-2 13:35
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