干细胞不像正常细胞，而是具有多能性，可以转变成为任何类型的细胞，从而为治疗很多疾病比如糖尿病、白血病等带来一定希望。然而截止到目前为止如何维持干细胞的多能性对科学家们而言依然是一项巨大的挑战，近日一项刊登于国际杂志ACS Central Science上的研究论文中，来自国外的研究人员通过研究发现，模仿昆虫的滞育过程或许可以抑制干细胞，从而就可以有选择性地使得干细胞“沉睡”长达两周。
近来研究者们发现，将多能干细胞生长于多种不同的表面或许可以促进干细胞分化为特殊类型的细胞，基于此前研究，本文研究中研究者Steve Armes及其同事就假设，合适的环境或许就可以阻断干细胞不断分化，提出这样的假设Armes表示，这或许来源于一些特殊的哺乳动物，比如袋鼠可以选择延迟怀孕，而该过程称之为胚胎滞育，目的在于确保后代可以在合适的环境中出生。
滞育的胚胎通常会被一层保护性的软组织粘膜所覆盖，因此研究者利用一种合成性的聚合物来开发非常柔软的水凝胶结构，从而模拟天然材料；当多能干细胞被置于水凝胶样结构中时，细胞就会在人体温度下从根本上停止生长及分化，而当降温使得凝胶成为液体状态后，干细胞就会在需要的时候被轻松移除，一旦移走后干细胞就会“苏醒”开始再次生长分化；这样的水凝胶样结构或许就可以被用来储存并且轻松运输干细胞。
最后研究者表示，当被置于上述水凝胶样结构中，人类胚胎就会进入到滞育状态，这就说明，简单地创造合适的物理环境对于延迟怀孕非常有效，而此前这种现象在人类胚胎中不曾被观察到。
摘要速递：
Mucin-Inspired Thermoresponsive Synthetic Hydrogels Induce Stasis in Human Pluripotent Stem Cells and Human Embryos
ACS Cent. Sci.
DOI: 10.1021/acscentsci.5b00370
February 10, 2016
Human pluripotent stem cells (hPSCs; both embryonic and induced pluripotent) rapidly proliferate in adherent culture to maintain their undifferentiated state. However, for mammals exhibiting delayed gestation (diapause), mucin-coated embryos can remain dormant for days or months in utero, with their constituent PSCs remaining pluripotent under these conditions. Here we report cellular stasis for both hPSC colonies and preimplantation embryos immersed in a wholly synthetic thermoresponsive gel comprising poly(glycerol monomethacrylate)-poly(2-hydroxypropyl methacrylate) [PGMA55-PHPMA135] diblock copolymer worms. This hydroxyl-rich mucin-mimicking nonadherent 3D gel maintained PSC viability and pluripotency in the quiescent G0 state without passaging for at least 14 days. Similarly, gel-coated human embryos remain in a state of suspended animation (diapause) for up to 8 days. The discovery of a cryptic cell arrest mechanism for both hPSCs and embryos suggests an important connection between the cellular mechanisms that evoke embryonic diapause and pluripotency. Moreover, such synthetic worm gels offer considerable utility for the short-term (weeks) storage of either pluripotent stem cells or human embryos without cryopreservation.
————引自“高分子科学前沿”
