Biohybrid cell-driven microsystems offer unparalleled possibilities for realization of soft microrobots at the micron scale. Here, we introduce a bacteria-driven microswimmer that combines the active locomotion and sensing capabilities of bacteria with the desirable encapsulation and viscoelastic properties of a soft double-micelle microemulsion for active transport and delivery of cargo (e.g., imaging agents, genes, and drugs) to living cells. Quasi-monodisperse double emulsions were synthesized with an aqueous core that encapsulated the fluorescence imaging agents, as a proof-of-concept cargo in this study, and an outer oil shell that was functionalized with streptavidin for specific and stable attachment of biotin-conjugated Escherichia coli. Motile bacteria effectively propelled the soft microswimmers across a Transwell membrane, actively delivering imaging agents (i.e., dyes) encapsulated inside of the micelles to a monolayer of cultured MCF7 breast cancer and J744A.1 macrophage cells, which enabled real-time, live-cell imaging of cell organelles, namely mitochondria, endoplasmic reticulum, and Golgi body. This in vitro model demonstrates the proof-of-concept feasibility of the proposed soft microswimmers and offers promise for potential biomedical applications in active and/or targeted transport and delivery of imaging agents, drugs, stem cells, siRNA, and therapeutic genes to live tissue in in vitro disease models (e.g., organ-on-a-chip devices) and stagnant or low-flow-velocity fluidic regions of the human body.

中文翻译：

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基于微乳液的软细菌驱动微泳器，用于主动递送货物

生物混合细胞驱动的微系统为实现微米级的软微型机器人提供了无与伦比的可能性。在这里，我们引入一个细菌驱动microswimmer，结合了有源运动和与所期望的封装细菌和主动运输和货物递送的软双胶束微乳液的粘弹性特性的感测能力（É。克。，显像剂，基因和药物）转移到活细胞中。合成了准单分散双乳状液，其水芯包裹了荧光显像剂，作为本研究的概念验证货物；外油壳经链霉亲和素功能化，可特异性和稳定地附着生物素结合的埃希氏菌。大肠杆菌。活动细菌有效地推动了软microswimmers跨越的Transwell膜，积极地递送成像剂（我。ê。染料）封装在胶束的内部培养的MCF7乳腺癌和J744A.1巨噬细胞单层，这使实时细胞器，即线粒体，内质网和高尔基体的活细胞成像。该体外模型证明了所提议的软微泳器在概念上的可行性，并为潜在的生物医学应用提供了希望，有望有效地和/或靶向地将显像剂，药物，干细胞，siRNA和治疗性基因转运到活组织中。在体外疾病模型（é。克（例如，芯片上的器官装置）和人体的停滞或低流速流体区域。