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Creators/Authors contains: "Davalos, Rafael_V"

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  1. Abstract Small‐scale robots capable of remote active steering and navigation offer great potential for biomedical applications. However, the current design and manufacturing procedure impede their miniaturization and integration of various diagnostic and therapeutic functionalities. Herein, submillimeter fiber robots that can integrate navigation, sensing, and modulation functions are presented. These fiber robots are fabricated through a scalable thermal drawing process at a speed of 4 meters per minute, which enables the integration of ferromagnetic, electrical, optical, and microfluidic composite with an overall diameter of as small as 250 µm and a length of as long as 150 m. The fiber tip deflection angle can reach up to 54ounder a uniform magnetic field of 45 mT. These fiber robots can navigate through complex and constrained environments, such as artificial vessels and brain phantoms. Moreover, Langendorff mouse hearts model, glioblastoma micro platforms, and in vivo mouse models are utilized to demonstrate the capabilities of sensing electrophysiology signals and performing a localized treatment. Additionally, it is demonstrated that the fiber robots can serve as endoscopes with embedded waveguides. These fiber robots provide a versatile platform for targeted multimodal detection and treatment at hard‐to‐reach locations in a minimally invasive and remotely controllable manner. 
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  2. Abstract Cancer stem cells (CSCs) are aggressive subpopulations with increased stem‐like properties. CSCs are usually resistant to most standard therapies and are responsible for tumor repropagation. Similar to normal stem cells, isolation of CSCs is challenging due to the lack of reliable markers. Antigen‐based sorting of CSCs usually requires staining with multiple markers, making the experiments complicated, expensive, and sometimes unreliable. Here, we study the feasibility of using dielectrophoresis (DEP) for isolation of glioblastoma cells with increased stemness. We culture a glioblastoma cell line in the form of neurospheres as an in vitro model for glioblastoma stem cells. We demonstrate that spheroid forming cells have higher expression of stem cell marker, nestin. Next, we show that dielectric properties of neurospheres change as a result of changing culture conditions. Our results indicate that spheroid forming cells need higher voltages to experience the same DEP force magnitude compared to normal monolayer cultures of glioblastoma cell line. This study confirms the possibility of using DEP to isolate glioblastoma stem cells. 
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