Department of Physics and WZMW, Philipps Universität Marburg, Marburg, Germany.
J Control Release. 2012 Apr 10;159(1):120-7. doi: 10.1016/j.jconrel.2011.12.013. Epub 2011 Dec 29.
Light-responsive microcapsules constructed by layer-by-layer self-assembly are used as microcarriers to deliver different macromolecules inside cells. The microcapsules carry the macromolecules as cargo in their cavity, while their walls are modified with agglomerated gold nanoparticles. Microcapsules are incorporated by living cells and are then located in lysosomal compartments. Controlled release of the encapsulated material from the interior of the capsule to the cytosol is possible upon NIR-light irradiation. This is based on local heating of the gold nanoparticles upon NIR light and disruption of the capsule wall, what results on release of encapsulated materials. We illustrate several key advances in controlled release induced by light. First, we demonstrate that capsules can be opened individually, which allows for sequentially releasing cargo from different capsules within one single cell. Second, by using a pH-indicator as cargo the claim of release from the acidic lysosomal compartments to the neutral cytosol is experimentally evident which until now has been only speculated. Third, green fluorescent protein (GFP) is released to the cytosol while retaining its functionality. This demonstrates that proteins can be released without destruction by the local heating. Fourth, GFP is also administered in biodegradable capsules, which leads to a different release mechanism compared to externally triggering for light-responsive microcapsules.
用光响应的层层自组装构建的微胶囊被用作微载体，将不同的生物大分子递送到细胞内。微胶囊将生物大分子作为货物装载在其腔体内，而其壁用聚集的金纳米粒子进行修饰。微胶囊被活细胞摄取，并随后定位于溶酶体隔室中。在近红外光照射下，通过内部胶囊的受控释放可以将封装材料释放到细胞质中。这是基于近红外光照射下金纳米粒子的局部加热和胶囊壁的破坏，导致封装材料的释放。我们说明了几种由光诱导的控制释放的关键进展。首先，我们证明可以单独打开胶囊，这允许从同一细胞内的不同胶囊中顺序释放货物。其次，通过使用 pH 指示剂作为货物，从酸性溶酶体隔室到中性细胞质的释放的主张在实验上得到了证明，这一点迄今为止只是推测。第三，绿色荧光蛋白（GFP）被释放到细胞质中，同时保持其功能。这表明可以在不被局部加热破坏的情况下释放蛋白质。第四，GFP 也被递送到可生物降解的胶囊中，与外部触发的光响应微胶囊相比，这导致了不同的释放机制。
