幹細胞論壇

 蘭嶼豬實驗 減少細胞壞死 生成新心血管

〔記者孟慶慈／台南報導〕罹患心肌梗塞（冠狀動脈阻塞），容易因血液無法正常供應以致心肌細胞壞死、心臟衰竭而死亡。成大醫學院助理教授謝清河及其團隊，以「心臟幹細胞療法」完成全球首例以大動物（豬）為對象的實驗，證明該療法可減少心肌細胞壞死，幹細胞更形成新的心血管，讓心臟幹細胞療法跨出一大步。

奈米纖維水膠提高幹細胞存活率

心臟幹細胞療法，主要是以多種胺基酸物質合成奈米纖維水膠，結合豬隻骨髓分離出的幹細胞，注入豬隻的心肌梗塞處。研究成果今年九月發表於心血管研究領域排名第一的國際期刊（Circulation），此一技術現正申請國內外專利。

謝清河表示，過去國際上所做的動物實驗研究，如果是直接將幹細胞注入心臟，存活率相當有限，注入一萬顆幹細胞，四十八小時後僅一顆活下來，有了奈米纖維水膠的幫忙，四十八小時後有一千顆活下來，且經二十八天的觀察，豬隻心肌壞死情況減少，水膠在緩慢的解化過程中，幹細胞也長出新的心血管。

謝清河指出，奈米纖維水膠為多年前成大與美國哈佛大學等共同研究的成果，內有胺基酸物質、生長因子等，該成果已以成大謝清河名義申請到美國專利。

相關實驗用了一百頭以上豬隻

謝清河表示，團隊多年前先以小鼠、大鼠等做實驗效果頗理想，一年多前開始著手大動物實驗，豬的心臟血液循環系統與人類相當，實驗的對象為體型較小的蘭嶼豬，前後用了約四十頭，若包括相關的研究則用了一百頭以上的豬。

謝清河說，團隊從豬身上抽取骨髓並分離出幹細胞，混入奈米纖維水膠，注入罹患心肌梗塞的豬隻心臟，總共注入兩西西、四十個位置；實驗過程設計完全仿照臨床治療施行的時機，前後只需三十分鐘。謝清河解釋，採血管注射法並不適合，幹細胞不一定會到達預定的位置，也擔心水膠阻塞血管，因此直接注射心臟受損處是較適當的方法。

盼透過基因轉植 讓幹細胞長出心肌細胞

謝清河表示，實驗目前證明奈米纖維水膠結合幹細胞，可以減少心肌壞死，並生成新的心血管，但還沒有做到心肌細胞再生的階段。不過，團隊已經著手進行「誘導性多潛能幹細胞技術」，希望透過基因轉植的技術，合成較容易長出心肌的幹細胞；但要到達讓幹細胞長出心肌細胞的階段，仍有一段很長的路要走。

A research team at National Cheng Kung University has conducted the world’s first successful experiments on large animals indicating that heart stem cell therapy can be used to reduce cardiac muscle cell damage and to form new cardiovascular vessels from stem cells.

Patrick C. H. Hsieh, assistant professor at NCKU’s Graduate Institute of Clinical Medicine, said Oct. 12 his research team combined self-assembling peptide nanofiber hydrogel with autologous bone marrow stem cells to inject into areas of cardiac infarction in the test animals.

The experiments were conducted on Lanyu miniature pigs, which have a similar cardiac structure to that of humans, Hsieh said.

The team’s breakthrough findings on the novel stem cell therapy for heart repair were published in the September 2010 issue of Circulation, the leading international journal in cardiovascular studies. Patent applications for the new technology have already been filed in Taiwan and abroad.

Hsieh explained that if stem cells are injected into the test animal’s heart, as past studies have done, the survival rate of the cells tends to be low. With the help of self-assembling peptide nanofiber hydrogel, the cell retention rate improved eight times in a month’s time, said Hsieh.

http://www.taiwantoday.tw/ct.asp?xItem=122258&ctNode=445

According to Hsieh, his school and Harvard University jointly made breakthroughs in nanofiber hydrogel research several years ago.

Hsieh, who is also a cardiovascular surgeon at NCKU Hospital, said the team started the heart stem cell therapy tests on Lanyu miniature pigs over a year ago following successful experiments on laboratory mice that began a few years earlier.

He stressed that while the team succeeded in forming new cardiovascular vessels from stem cells, it was not able to regenerate heart tissue. (SB)