RESUMEN
Optical tweezers have provided tremendous opportunities for fundamental studies and applications in the life sciences, chemistry, and physics by offering contact-free manipulation of small objects. However, it requires sophisticated real-time imaging and feedback systems for conventional optical tweezers to achieve controlled motion of micro/nanoparticles along textured surfaces, which are required for such applications as high-resolution near-field characterizations of cell membranes with nanoparticles as probes. In addition, most optical tweezers systems are limited to single manipulation modes, restricting their broader applications. Herein, we develop an optothermal platform that enables the multimodal manipulation of micro/nanoparticles along various surfaces. Specifically, we achieve the manipulation of micro/nanoparticles through the synergy between the optical and thermal forces, which arise due to the temperature gradient self-generated by the particles absorbing the light. With a simple control of the laser beam, we achieve five switchable working modes [i.e., tweezing, rotating, rolling (toward), rolling (away), and shooting] for the versatile manipulation of both synthesized particles and biological cells along various substrates. More interestingly, we realize the manipulation of micro/nanoparticles on rough surfaces of live worms and their embryos for localized control of biological functions. By enabling the three-dimensional control of micro/nano-objects along various surfaces, including topologically uneven biological tissues, our multimodal optothermal platform will become a powerful tool in life sciences, nanotechnology, and colloidal sciences.
RESUMEN
Optical manipulation of tiny objects has benefited many research areas ranging from physics to biology to micro/nanorobotics. However, limited manipulation modes, intense lasers with complex optics, and applicability to limited materials and geometries of objects restrict the broader uses of conventional optical tweezers. Herein, we develop an optothermal platform that enables the versatile manipulation of synthetic micro/nanoparticles and live cells using an ultralow-power laser beam and a simple optical setup. Five working modes (i.e., printing, tweezing, rotating, rolling, and shooting) have been achieved and can be switched on demand through computer programming. By incorporating a feedback control system into the platform, we realize programmable multimodal control of micro/nanoparticles, enabling autonomous micro/nanorobots in complex environments. Moreover, we demonstrate in situ three-dimensional single-cell surface characterizations through the multimodal optothermal manipulation of live cells. This programmable multimodal optothermal platform will contribute to diverse fundamental studies and applications in cellular biology, nanotechnology, robotics, and photonics.
Asunto(s)
Pinzas Ópticas , Óptica y Fotónica , Rayos Láser , Nanotecnología/métodos , Membrana CelularRESUMEN
Despite its wide establishment over the years, iron oxide nanoparticle (IONP) still draws extensive interest in the biomedical fields due to its biocompatibility, biodegradability, magnetivity and surface tunable properties. IONP has been used for the MRI, magnetic targeting, drug delivery and hyperthermia of various diseases. However, their poor stability, low diagnostic sensitivity and low disease-specificity have resulted in unsatisfying diagnostic and therapeutic outputs. The surface functionalization of IONP with biocompatible and colloidally stable components appears to be promising to improve its circulation and colloidal stability. Importantly, through surface functionalization with designated functional components, IONP-based assemblies with multiple stimuli-responsivity could be formed to achieve an accurate and efficient delivery of IONP to disease sites for an improved disease diagnosis and therapy. In this work, we first described the design of biocompatible and stable IONP assemblies. Further, their stimuli-driven manipulation strategies are reviewed. Next, the utilization of IONP assemblies for disease diagnosis, therapy and imaging-guided therapy are discussed. Then, the potential toxicity of IONPs and their clinical usages are described. Finally, the intrinsic challenges and future outlooks of IONP assemblies are commented. This review provides recent insights into IONP assemblies, which could inspire researchers on the future development of multi-responsive and disease-targetable nanoassemblies for biomedical utilization.