Franklin Daniel, Ueltschi Tyler, Carlini Andrea, Yao Shenglian, Reeder Jonathan, Richards Benjamin, Van Duyne Richard P, Rogers John A
Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States.
Querrey-Simpson Institute for Bioelectronics, Northwestern University, Evanston, Illinois 60208, United States.
ACS Nano. 2021 Feb 23;15(2):2327-2339. doi: 10.1021/acsnano.0c10234. Epub 2021 Jan 13.
Minimally invasive methods for temperature sensing and thermal modulation in living tissues have extensive applications in biological research and clinical care. As alternatives to bioelectronic devices for this purpose, functional nanomaterials that self-assemble into optically active microstructures offer important features in remote sensing, injectability, and compact size. This paper introduces a transient, or bioresorbable, system based on injectable slurries of well-defined microparticles that serve as photopumped lasers with temperature-sensitive emission wavelengths (>4-300 nm °C). The resulting platforms can act as tissue-embedded thermal sensors and, simultaneously, as distributed vehicles for thermal modulation. Each particle consists of a spherical resonator formed by self-organized cholesteric liquid crystal molecules doped with fluorophores as gain media, encapsulated in thin shells of soft hydrogels that offer adjustable rates of bioresorption through chemical modification. Detailed studies highlight fundamental aspects of these systems including particle sensitivity, lasing threshold, and size. Additional experiments explore functionality as photothermal agents with active temperature feedback (Δ = 1 °C) and potential routes in remote evaluation of thermal transport properties. Cytotoxicity evaluations support their biocompatibility, and demonstrations in Casper fish illustrate their ability to measure temperature within biological tissues with resolution of 0.01 °C. This collective set of results demonstrates a range of multifunctional capabilities in thermal sensing and modulation.
用于活体组织温度传感和热调制的微创方法在生物学研究和临床护理中有广泛应用。作为用于此目的的生物电子设备的替代方案，自组装成光学活性微结构的功能性纳米材料在遥感、可注射性和紧凑尺寸方面具有重要特性。本文介绍了一种基于可注射的明确定义的微粒浆料的瞬态或可生物吸收系统，这些微粒用作具有温度敏感发射波长（>4 - 300 nm/°C）的光泵浦激光器。由此产生的平台可以充当组织嵌入式热传感器，同时作为热调制的分布式载体。每个粒子由一个球形谐振器组成，该谐振器由掺杂有荧光团作为增益介质的自组织胆甾相液晶分子形成，封装在软水凝胶薄壳中，通过化学修饰可提供可调节的生物吸收速率。详细研究突出了这些系统的基本方面，包括粒子灵敏度、激光阈值和尺寸。额外的实验探索了作为具有主动温度反馈（Δ = 1°C）的光热剂的功能以及远程评估热传输特性的潜在途径。细胞毒性评估支持它们的生物相容性，并且在卡斯珀鱼中的演示说明了它们以0.01°C的分辨率测量生物组织内温度的能力。这一系列结果展示了热传感和调制方面的一系列多功能能力。
