Pieper Maria I, Mathews Hannah F, Pich Andrij
DWI-Leibniz Institute for Interactive Materials e.V., RWTH Aachen University, Forckenbeckstr. 50, 52074, Aachen, Germany.
Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany.
Small. 2025 Mar;21(9):e2410221. doi: 10.1002/smll.202410221. Epub 2025 Jan 15.
Compartmentalization is crucial for control over complex biological cascade reactions. In microgels, the formation of discrete compartments allows for simultaneous uptake and orthogonal release of physicochemically distinct drugs, among others. However, many state-of-the-art approaches yielding compartmentalized microgels require the use of specific, though not always biocompatible, components and temperatures well above the physiological range, which may damage possible biological cargo. Therefore, a novel technique to fabricate compartmentalized microgels by exploiting ionic strength-induced precipitation as a mechanism for compartmentalization is developed. For this, a droplet-based microfluidic approach in which preformed nanogels are incorporated into poly(N-isopropylacrylamide)- or poly(acrylamide)-based microgels is employed. Allowing contact between the nanogel-monomer mixture and a salt solution only at the cross junction inhibits premature precipitation of the nanogels and aggregates form on the chip. It is demonstrated that this method is applicable to a variety of nanogel species in both stimuli-responsive and non-stimuli-responsive microgel networks. For temperature-responsive nanogel compartments in non-responsive microgels, anisotropic shape change is investigated by adjusting temperature or salt concentration or changing the solvent. Lastly, an exemplary uptake and release experiment demonstrates highly selective drug absorption, paving the way for more advanced biomimetic polymer structures.
区室化对于控制复杂的生物级联反应至关重要。在微凝胶中，离散区室的形成使得能够同时摄取和正交释放物理化学性质不同的药物等物质。然而，许多产生区室化微凝胶的先进方法需要使用特定的（尽管并非总是生物相容的）组分以及远高于生理范围的温度，这可能会损坏潜在的生物负载。因此，开发了一种通过利用离子强度诱导沉淀作为区室化机制来制备区室化微凝胶的新技术。为此，采用基于液滴的微流控方法，其中将预先形成的纳米凝胶掺入基于聚（N-异丙基丙烯酰胺）或聚（丙烯酰胺）的微凝胶中。仅在交叉点处允许纳米凝胶-单体混合物与盐溶液接触可抑制纳米凝胶的过早沉淀，并在芯片上形成聚集体。结果表明，该方法适用于刺激响应性和非刺激响应性微凝胶网络中的多种纳米凝胶种类。对于非响应性微凝胶中的温度响应性纳米凝胶区室，通过调节温度或盐浓度或改变溶剂来研究各向异性形状变化。最后，一个示例性的摄取和释放实验证明了高度选择性的药物吸收，为更先进的仿生聚合物结构铺平了道路。
