title: Carbonate-based Janus micromotors moving in ultra-light acidic environment generated by HeLa cells in situ.
abstract: 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.
authors.affiliation: Institute for Integrative Nanosciences, Leibniz Institute for Solid State and Materials Research Dresden, 01069 Dresden, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Guix
authors.affiliation: Institute for Integrative Nanosciences, Leibniz Institute for Solid State and Materials Research Dresden, 01069 Dresden, Germany.
authors.forename: Anne K
authors.initials: AK
authors.lastname: Meyer
authors.affiliation: Institute for Integrative Nanosciences, Leibniz Institute for Solid State and Materials Research Dresden, 01069 Dresden, Germany.
authors.forename: Britta
authors.initials: B
authors.lastname: Koch
authors.affiliation: 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.|Center for Advancing Electronics Dresden, Dresden University of Technology, 01187 Dresden, Germany.
authors.forename: Oliver G
authors.initials: OG
authors.lastname: Schmidt
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D017077:Culture Media, Conditioned / Q000737:chemistry; D016503:Drug Delivery Systems; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009038:Motion; D059016:Tumor Microenvironment
chemical_list: D017077:Culture Media, Conditioned; D002119:Calcium Carbonate