Guix Maria, Meyer Anne K, Koch Britta, Schmidt Oliver G
Institute for Integrative Nanosciences, Leibniz Institute for Solid State and Materials Research Dresden, 01069 Dresden, Germany.
Material Systems for Nanoelectronics, Chemnitz University of Technology, 09126 Chemnitz, Germany.
Sci Rep. 2016 Feb 24;6:21701. doi: 10.1038/srep21701.
Novel approaches to develop naturally-induced drug delivery in tumor environments in a deterministic and controlled manner have become of growing interest in recent years. Different polymeric-based microstructures and other biocompatible substances have been studied taking advantage of lactic acidosis phenomena in tumor cells, which decrease the tumor extracellular pH down to 6.8. Micromotors have recently demonstrated a high performance in living systems, revealing autonomous movement in the acidic environment of the stomach or moving inside living cells by using acoustic waves, opening the doors for implementation of such smart microengines into living entities. The need to develop biocompatible motors which are driven by natural fuel sources inherently created in biological systems has thus become of crucial importance. As a proof of principle, we here demonstrate calcium carbonate Janus particles moving in extremely light acidic environments (pH 6.5), whose motion is induced in conditioned acidic medium generated by HeLa cells in situ. Our system not only obviates the need for an external fuel, but also presents a selective activation of the micromotors which promotes their motion and consequent dissolution in presence of a quickly propagating cell source (i.e. tumor cells), therefore inspiring new micromotor configurations for potential drug delivery systems.
近年来，以确定性和可控方式在肿瘤环境中开发自然诱导药物递送的新方法越来越受到关注。利用肿瘤细胞中的乳酸酸中毒现象，研究了不同的基于聚合物的微观结构和其他生物相容性物质，这种现象会使肿瘤细胞外pH值降至6.8。微型马达最近在生物系统中展现出高性能，在胃部酸性环境中显示出自主运动，或通过声波在活细胞内移动，为将这种智能微型发动机应用于生物实体打开了大门。因此，开发由生物系统中固有天然燃料源驱动的生物相容性马达变得至关重要。作为原理验证，我们在此展示了碳酸钙双面粒子在极轻度酸性环境（pH 6.5）中的移动，其运动是由HeLa细胞原位产生的条件酸性介质诱导的。我们的系统不仅无需外部燃料，还呈现出微型马达的选择性激活，这促进了它们在快速增殖细胞源（即肿瘤细胞）存在时的运动及随后的溶解，因此为潜在药物递送系统激发了新的微型马达配置。
