利用奈米技術改善人工受孕治療---單一精子分離與高篩選率流道

Abstract

人工受孕是不孕症患者的一大福音，如何篩選出最好的精子以供卵子受孕是重點之 一，而目前的人工受孕治療技術中，精子的篩選仍是問題之ㄧ。就現有的篩選方法而言， 對於人工受孕(IUI)來說篩選率過低，這會導致成功率的下降。而顯微注射法(ICSI)中， 問題在於無法準確的挑出最好的精子。本計劃之目的在於改善現有的人工受孕技術，目 標為利用全像光學鑷夾(holographic optical tweezers, HOT)系統研發準確的單一精子分離 技術，改善ICSI 的精子篩選過程；利用三維的微流道篩選出所有具有泳動力之精子， 提高精子篩選率，使IUI 成功機率上升。最後，依據醫院的需求做改善，以求應用之實 用性。各年目標略述如下： 第一年： 旨在研發準確的單一精子分離技術。此技術的重要性在於我們可以在 一群精子或是雜碎組織中，準確且快速的單獨分離出一個目標精子，使用 HOT 系統並以目標精子為中心，清空其四週，並用微吸管吸出，達成準確 且單一分離之目的，此種用微吸管吸出的應用方式符合目前醫院的操作過 程，希望可以改善目前TESE 與ICSI 所遇到的問題。 第二年： 目的在解決IUI 中精子數量不夠導致成功率不高的問題，利用三維的 微流道設計以篩選出更多的具活動力之精子，提高篩選率，期待能達成高 篩選率之目標。 第三年： 承續前兩年，為了使我們開發的技術更貼合醫院的應用，第三年計畫 將針對這些計畫做改良與近一步檢驗。 改良部分首先考慮醫院的需求，HOT 的單一精子分離中，預計縮小 系統之體積，使用光纖傳導雷射光減少光路的耦合，達到方便且可攜之目 的。高篩選率三維流道的改良方向，則是取決於當下醫院的看法。 檢驗部分，首先檢驗單一精子分離系統中雷射造成之光傷害，比較 1064nm 與980nm 光傷害的差異，找出最好的波長；此外我們將藉由改變 培養液之折射率，使其折射率高於精子，精子得以被推離光焦點，雷射光 穿過精子的比例變少以降低雷射鑷夾之光傷害。 高篩選率的三維流道方面，我們將做更進一步的分析，方法可以有 泳動速度、活化比例、頂體反應比例、IVF 比例、精子表面的AFM 分析 等，利用這些參數檢驗精子的品質，期待得到此種方法篩選出的精子品質 皆佳的結果。

Assisted productive technology(APT) is a good news for the patients with vibriosis. There is always a important issue for APT that how to sort a good sperm for an ovum and the sperm sorting is still a problem for nowadays technology. For intrauterine insemination(IUI), the less sperms after sorting, the less probably IUI would work. For intracytoplasmic sperm injection(ICSI), it’s hard to get the best sperm by sorting. The purposes in this plan are to improve the APT nowadays. We use the holographic optical tweezers(HOT) system to help sort a single sperm accurately and fast. It’s a necessary technology for ICSI. We design a 3D micro-channel to promote the sorting rate by select all the sperms with motive force. It can raise the success probability of IUI. All our efforts target on the final application in hospital . The goals of every year are described below: 1st year : We will try to develop the single sperm sorting technology which can suck the specific sperm by a micro-pipet in a crowd of tissue fragments accurately and fast. We use HOT system to clean the surroundings so that a micro-pipet can suck the specific sperm without the interference of tissue fragments. The sperm sucking by a micro-pipet is the same as the applied way in the hospital. We hope that the technology can help improve the ICSI technique. 2nd year : We will try to design a 3D micro-channel to promote the sorting rate by select all the sperms with motive force. It can solve the problem of low success probability of IUI which is caused by the low sorting rate of sperms. 3rd year : To push our development forward to real application, we will try to improvement the design of the results in 1st and 2nd year. We will try everything as long as the hospital want to suit our design to application. In our thinking now, we want to try to setup a portable HOT system. We will exam the photo damage made by HOT system, too. We want to use a laser source with the wavelength of 980nm to compare with the wavelength of 1064nm. We also want to change the value of the refraction index of surroundings(medium) so that the sperm will be pulled away from the focus point of laser. The photo damage will be less because there are less rays pass through the sperm. For 3D micro-channel, we will analyze the sperms after sorting and exam the quality of them. We hope the result will be fine so that our 3D micro-channel’s function is proved.