Tunable Acoustic Tweezer System for Precise Three-Dimensional Particle Manipulation.

This study introduces a tunable acoustic tweezer system designed for precise three-dimensional particle trapping and manipulation. The system utilizes a dual-liquid-layer acoustic lens, which enables the dynamic control of the focal length through the adjustable curvature of a latex membrane. This tunability is essential for generating the acoustic forces necessary for effective manipulation of particles, particularly along the direction of acoustic wave propagation (z-axis).

Color-Transfer-Enhanced Data Construction and Validation for Deep Learning-Based Upper Gastrointestinal Landmark Classification in Wireless Capsule Endoscopy.

While the adoption of wireless capsule endoscopy (WCE) has been steadily increasing, its primary application remains limited to observing the small intestine, with relatively less application in the upper gastrointestinal tract. However, there is a growing anticipation that advancements in capsule endoscopy technology will lead to a significant increase in its application in upper gastrointestinal examinations. This study addresses the underexplored domain of landmark identification within the upper gastrointestinal tract using WCE, acknowledging the limited research and public datasets available in this emerging field.

Acoustic Actuators for the Manipulation of Micro/Nanorobots: State-of-the-Art and Future Outlooks.

Compared to other actuating methods, acoustic actuators offer the distinctive capability of the contactless manipulation of small objects, such as microscale and nanoscale robots. Furthermore, they have the ability to penetrate the skin, allowing for the trapping and manipulation of micro/nanorobots that carry therapeutic agents in diverse media. In this review, we summarize the current progress in using acoustic actuators for the manipulation of micro/nanorobots used in various biomedical applications.

Ultrasonic Manipulation of Hydrodynamically Driven Microparticles in Vessel Bifurcation: Simulation, Optimization, Experimental Validation, and Potential for Targeted Drug Delivery.

Microrobots driven by multiple external power sources have emerged as promising tools for targeted drug and stem cell delivery in tissue regeneration. However, navigating and imaging these devices within a complex colloidal vascular system at a clinical scale is challenging. Ultrasonic actuators have gained interest in the field of non-contact manipulation of micromachines due to their label-free biocompatible nature and safe operation history.

Magnetic particle image scanner based on asymmetric core-filled electromagnetic actuator.

Monitoring the distribution of magnetic nanoparticles (MNPs) in the vascular system is an important task for the advancement of precision therapeutics and drug delivery. Despite active targeting using active motilities, it is required to visualize the position and concentration of carriers that reach the target, to promote the development of this technology. In this work, a feasibility study is presented on a tomographic scanner that allows monitoring of the injected carriers quantitatively in a relatively short interval.

Macrophage-Based Microrobots for Anticancer Therapy: Recent Progress and Future Perspectives.

Macrophages, which are part of the mononuclear phagocytic system, possess sensory receptors that enable them to target cancer cells. In addition, they are able to engulf large amounts of particles through phagocytosis, suggesting a potential "Trojan horse" drug delivery approach to tumors by facilitating the engulfment of drug-hidden particles by macrophages. Recent research has focused on the development of macrophage-based microrobots for anticancer therapy, showing promising results and potential for clinical applications.

Four-Dimensional-Printed Microrobots and Their Applications: A Review.

Owing to their small size, microrobots have many potential applications. In addition, four-dimensional (4D) printing facilitates reversible shape transformation over time or upon the application of stimuli. By combining the concept of microrobots and 4D printing, it may be possible to realize more sophisticated next-generation microrobot designs that can be actuated by applying various stimuli, and also demonstrates profound implications for various applications, including drug delivery, cells delivery, soft robotics, object release and others.

Functional enhancement of exosomes derived from NK cells by IL-15 and IL-21 synergy against hepatocellular carcinoma cells: The cytotoxicity and apoptosis in vitro study.

Exosomes are released by various cells, including natural killer (NK) cells and transport signaling molecules for the intercellular communication. Hepatocellular carcinoma (HCC), also known as primary liver cancer, is often inoperable and difficult to accurate diagnosis. Notably, the prognosis and underlying mechanisms of HCC are not fully understood.

Magnetically Actuated Microscaffold with Controllable Magnetization and Morphology for Regeneration of Osteochondral Tissue.

Magnetic microscaffolds capable of targeted cell delivery have been developed for tissue regeneration. However, the microscaffolds developed so far with similar morphologies have limitations for applications to osteochondral disease, which requires simultaneous treatment of the cartilage and subchondral bone. This study proposes magnetically actuated microscaffolds tailored to the cartilage and subchondral bone for osteochondral tissue regeneration, named magnetically actuated microscaffolds for cartilage regeneration (MAM-CR) and for subchondral bone regeneration (MAM-SBR).

Wearable Localized Surface Plasmon Resonance-Based Biosensor with Highly Sensitive and Direct Detection of Cortisol in Human Sweat.

Wearable biosensors have the potential for developing individualized health evaluation and detection systems owing to their ability to provide continuous real-time physiological data. Among various wearable biosensors, localized surface plasmon resonance (LSPR)-based wearable sensors can be versatile in various practical applications owing to their sensitive interactions with specific analytes. Understanding and analyzing endocrine responses to stress is particularly crucial for evaluating human performance, diagnosing stress-related diseases, and monitoring mental health, as stress takes a serious toll on physiological health and psychological well-being.

Fabrication, Acoustic Characterization and Phase Reference-Based Calibration Method for a Single-Sided Multi-Channel Ultrasonic Actuator.

The ultrasonic actuator can be used in medical applications because it is label-free, biocompatible, and has a demonstrated history of safe operation. Therefore, there is an increasing interest in using an ultrasonic actuator in the non-contact manipulation of micromachines in various materials and sizes for therapeutic applications. This research aims to design, fabricate, and characterize a single-sided transducer array with 56 channels operating at 500 kHz, which provide benefits in the penetration of tissue.

Battery-Free Tattooing Mechanism-Based Functional Active Capsule Endoscopy.

This paper presents a novel tattooing capsule endoscope (TCE) for delivering a certain amount of ink to the submucosal layer of digestive tract organs. A dual-function permanent magnet is used for locomotion and injection activation. The developed capsule endoscope can move actively in 5 DOF due to the interaction between the permanent magnet and a controllable external magnetic field produced by an electromagnet actuation system.

Multifunctional microrobot with real-time visualization and magnetic resonance imaging for chemoembolization therapy of liver cancer.

Microrobots that can be precisely guided to target lesions have been studied for in vivo medical applications. However, existing microrobots have challenges in vivo such as biocompatibility, biodegradability, actuation module, and intra- and postoperative imaging. This study reports microrobots visualized with real-time x-ray and magnetic resonance imaging (MRI) that can be magnetically guided to tumor feeding vessels for transcatheter liver chemoembolization in vivo.

Microrobot with Gyroid Surface and Gold Nanostar for High Drug Loading and Near-Infrared-Triggered Chemo-Photothermal Therapy.

The use of untethered microrobots for precise synergistic anticancer drug delivery and controlled release has attracted attention over the past decade. A high surface area of the microrobot is desirable to achieve greater therapeutic effect by increasing the drug load. Therefore, various nano- or microporous microrobot structures have been developed to load more drugs.

Acoustically Driven Cell-Based Microrobots for Targeted Tumor Therapy.

Targeted drug delivery using microrobots manipulated by an external actuator has significant potential to be a practical approach for wireless delivery of therapeutic agents to the targeted tumor. This work aimed to develop a novel acoustic manipulation system and macrophage-based microrobots (Macbots) for a study in targeted tumor therapy. The Macbots containing superparamagnetic iron oxide nanoparticles (SPIONs) can serve as drug carriers.

Delivery of human natural killer cell-derived exosomes for liver cancer therapy: an in vivo study in subcutaneous and orthotopic animal models.

Exosomes are nanosized extracellular vesicles secreted by various cell types, including those of the immune system, such as natural killer (NK) cells. They play a role in intercellular communication by transporting signal molecules between the cells. Recent studies have reported that NK cell-derived exosomes (NK-exo) contain cytotoxic proteins-induced cell death.

Tumor-derived extracellular vesicles for the active targeting and effective treatment of colorectal tumors .

Colorectal cancer remains one of the main causes of cancer-related deaths worldwide. Although numerous nanomedicine formulations have been developed to tackle the disease, their low selectivity still limits effective therapeutic outcomes. In this study, we isolated extracellular vesicles (EVs) from CT26 colorectal cancer cells and 4T1 murine mammary carcinoma cells, loaded them with the chemotherapeutic agent (doxorubicin, DOX).

Holographic Acoustic Tweezers for 5-DoF Manipulation of Nanocarrier Clusters toward Targeted Drug Delivery.

Acoustic tweezers provide unique capabilities in medical applications, such as contactless manipulation of small objects (e.g., cells, compounds or living things), from nanometer-sized extracellular vesicles to centimeter-scale structures.

Shape-Tunable UV-Printed Solid Drugs for Personalized Medicine.

Several recent advances have emerged in biotherapy and the development of personal drugs. However, studies exploring effective manufacturing methods of personal drugs remain limited. In this study, solid drugs based on poly(ethylene glycol)diacrylate (PEGDA) hydrogel and doxorubicin were fabricated, and their final geometry was varied through UV-light patterning.

Magnetically controlled reversible shape-morphing microrobots with real-time X-ray imaging for stomach cancer applications.

Stomach cancer is a global health concern as millions of cases are reported each year. In the present study, we developed a pH-responsive microrobot with good biocompatibility, magnetic-field controlled movements, and the ability to be visualized X-ray imaging. The microrobot consisted of composite resin and a pH-responsive layer.

Human-robot-robot cooperative control using positioning robot and 1-DOF traction device for robot-assisted fracture reduction system.

While performing musculoskeletal long bone fracture reduction surgery, assistant surgeons can often suffer from physical fatigue as they provide resistance against the tension from surrounding muscles pulling on the patient's broken bones. These days, robotic systems are being actively developed to mitigate this physical workload by realigning and holding these fractured bones for surgeons. This has led to one consortium proposing the development of a robot-assisted fracture reduction system consisting of a 6-DOF positioning robot along with a 1-DOF traction device.

Programmed Shape-Morphing Material Using Single-Layer 4D Printing System.

The single-layer 4D printing technology that can be controllable in response to external stimuli is a tremendous challenge in many areas, including smart materials, robotics, and drug delivery systems. The single-layer 4D printing technique was enabled by light-focusing, which results in the difference of mechanical properties such as the coefficient of thermal expansion or Young's modulus between focused and unfocused regions. However, 4D printing to the desired shape using single-layered material is challenging.

Tripolar Electrode Electrochemical Impedance Spectroscopy for Endoscopic Devices toward Early Colorectal Tumor Detection.

Embedded sensors for endoscopy devices have been studied toward a convenient and decision-supportive methodology in colorectal cancer (CRC) diagnosis, but no device could provide direct CRC screening with measurements. In this study, we proposed a millimeter-scale electrical impedance spectroscopy (EIS) device that can be integrated into a biopsy tool in endoscopy for colorectal tumor detection. A minimally invasive tripolar electrode was designed to sense the tissue impedance, and a multilayer neural network was implemented for the classification algorithm.

Sonazoid-Conjugated Natural Killer Cells for Tumor Therapy and Real-Time Visualization by Ultrasound Imaging.

Various cell therapy strategies, including chimeric antigen receptor-expressing T or natural killer (NK) cells and cell-mediated drug delivery, have been developed for tumor eradication. However, the efficiency of these strategies against solid tumors remains unclear. We hypothesized that real-time control and visualization of therapeutic cells, such as NK cells, would improve their therapeutic efficacy against solid tumors.

Automated Bowel Polyp Detection Based on Actively Controlled Capsule Endoscopy: Feasibility Study.

This paper presents an active locomotion capsule endoscope system with 5D position sensing and real-time automated polyp detection for small-bowel and colon applications. An electromagnetic actuation system (EMA) consisting of stationary electromagnets is utilized to remotely control a magnetic capsule endoscope with multi-degree-of-freedom locomotion. For position sensing, an electronic system using a magnetic sensor array is built to track the position and orientation of the magnetic capsule during movement.