"This needle is still sharp enough to penetrate through body tissue.

VOA: special.2010.02.10

Many of them are derived from cholesterol and they're hydrophobic, which means they can penetrate through cell membranes.

多数分子都来自于胆固醇,它们是疏水性的,这意味着它们能够穿过细胞膜

耶鲁公开课 - 生物医学工程探索课程节选