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Various magnetic microcarrier systems capable of transporting cells to target lesions are developed for therapeutic agent-based tissue regeneration. However, the need for bioactive molecules and cells, the potential toxicity of the microcarrier, and the large volume and limited workspace of the magnetic targeting device remain challenging issues associated with microcarrier systems. Here, a multifunctional magnetic implant system is presented for targeted delivery, secure fixation, and induced differentiation of stem cells. This magnetic implant system consists of a biomaterial-based microcarrier containing bioactive molecules, a portable magnet array device, and a biocompatible paramagnetic implant. Among biomedical applications, the magnetic implant system is developed for knee cartilage repair. The various functions of these components are verified through in vitro, phantom, and ex vivo tests. As a result, a single microcarrier can load ≈1.52 ng of transforming growth factor β (TGF-β1) and 3.3 × 103 of stem cells and stimulate chondrogenic differentiation without extra bioactive molecule administration. Additionally, the implant system demonstrates high targeting efficiency (over 90%) of the microcarriers in a knee phantom and ex vivo pig knee joint. The results show that this implant system, which overcomes the limitations of the existing magnetic targeting system, represents an important advancement in the field.
Gwangjun Go; Ami Yoo; Seokjae Kim; Jong Keun Seon; Chang‐Sei Kim; Jong‐Oh Park; Eunpyo Choi. Magnetization‐Switchable Implant System to Target Delivery of Stem Cell‐Loaded Bioactive Polymeric Microcarriers. Advanced Healthcare Materials 2021, 2100068 .
AMA StyleGwangjun Go, Ami Yoo, Seokjae Kim, Jong Keun Seon, Chang‐Sei Kim, Jong‐Oh Park, Eunpyo Choi. Magnetization‐Switchable Implant System to Target Delivery of Stem Cell‐Loaded Bioactive Polymeric Microcarriers. Advanced Healthcare Materials. 2021; ():2100068.
Chicago/Turabian StyleGwangjun Go; Ami Yoo; Seokjae Kim; Jong Keun Seon; Chang‐Sei Kim; Jong‐Oh Park; Eunpyo Choi. 2021. "Magnetization‐Switchable Implant System to Target Delivery of Stem Cell‐Loaded Bioactive Polymeric Microcarriers." Advanced Healthcare Materials , no. : 2100068.
As wireless capsule endoscope (WCE) technology has advanced, various studies were published on WCEs with functional modules for the diagnosis and treatment of problems in the digestive system. However, when additional functional modules are added the physical size of the WCEs will increase, making them more difficult for patients to comfortably swallow. Moreover, there are limitations when it comes to adding multi-functional modules to the WCEs due to the size of the digestive tract itself. This article introduces a controllable modular capsule endoscope driven by an electromagnetic actuation (EMA) system. The modular capsules are divided into a driving capsule and a functional capsule. Capsules with different functions are swallowed in sequence and then recombination, transportation and separation functions are carried out under the control of the EMA system while in the stomach, this approach solves the size limitation issues faced by multi-functional capsule endoscopes. The recombination and separation functions make use of a characteristic of soft magnetic materials so that their magnetization direction can be changed easily. These functions are made possible by the addition of a soft magnet to the capsule together with the precise control of magnetic fields provided by the EMA system.
Zhenyu Li; Manh Hoang; Chang-Sei Kim; Eunpyo Choi; Doyeon Bang; Jong-Oh Park; Byungjeon Kang. Modular Capsules with Assembly and Separation Mechanism: Proof of Concept. Actuators 2021, 10, 159 .
AMA StyleZhenyu Li, Manh Hoang, Chang-Sei Kim, Eunpyo Choi, Doyeon Bang, Jong-Oh Park, Byungjeon Kang. Modular Capsules with Assembly and Separation Mechanism: Proof of Concept. Actuators. 2021; 10 (7):159.
Chicago/Turabian StyleZhenyu Li; Manh Hoang; Chang-Sei Kim; Eunpyo Choi; Doyeon Bang; Jong-Oh Park; Byungjeon Kang. 2021. "Modular Capsules with Assembly and Separation Mechanism: Proof of Concept." Actuators 10, no. 7: 159.
Macrophages (MΦs) have the capability to sense chemotactic cues and to home tumors, therefore presenting a great approach to engineer these cells to deliver therapeutic agents to treat diseases. However, current cell-based drug delivery systems usually use commercial cell lines that may elicit an immune response when injected into a host animal. Furthermore, premature off-target drug release also remains an enormous challenge. Here, we isolated and differentiated MΦs from the spleens of BALB/c mice and developed dual-targeting MΦ-based microrobots, regulated by chemotaxis and an external magnetic field, and had a precise spatiotemporal controlled drug release at the tumor sites in response to the NIR laser irradiation. These microrobots were prepared by coloading citric acid (CA)-coated superparamagnetic nanoparticles (MNPs) and doxorubicin (DOX)-containing thermosensitive nanoliposomes (TSLPs) into the MΦs. CA-MNPs promoted a magnetic targeting function to the microrobots and also permitted photothermal heating in response to the NIR irradiation, triggering drug release from TSLPs. In vitro experiments showed that the microrobots effectively infiltrated tumors in 3D breast cancer tumor spheroids, particularly in the presence of the magnetic field, and effectively induced tumor cell death, further enhanced by the NIR laser irradiation. In vivo experiments confirmed that the application of the magnetic field and NIR laser could markedly inhibit the growth of tumors with a subtherapeutic dose of DOX and a single injection of the microrobots. In summary, the study proposes a strategy for the effective anticancer treatment using the developed microrobots.
Van Du Nguyen; Hyun-Ki Min; Ho Yong Kim; Jiwon Han; You Hee Choi; Chang-Sei Kim; Jong-Oh Park; Eunpyo Choi. Primary Macrophage-Based Microrobots: An Effective Tumor Therapy In Vivo by Dual-Targeting Function and Near-Infrared-Triggered Drug Release. ACS Nano 2021, 15, 8492 -8506.
AMA StyleVan Du Nguyen, Hyun-Ki Min, Ho Yong Kim, Jiwon Han, You Hee Choi, Chang-Sei Kim, Jong-Oh Park, Eunpyo Choi. Primary Macrophage-Based Microrobots: An Effective Tumor Therapy In Vivo by Dual-Targeting Function and Near-Infrared-Triggered Drug Release. ACS Nano. 2021; 15 (5):8492-8506.
Chicago/Turabian StyleVan Du Nguyen; Hyun-Ki Min; Ho Yong Kim; Jiwon Han; You Hee Choi; Chang-Sei Kim; Jong-Oh Park; Eunpyo Choi. 2021. "Primary Macrophage-Based Microrobots: An Effective Tumor Therapy In Vivo by Dual-Targeting Function and Near-Infrared-Triggered Drug Release." ACS Nano 15, no. 5: 8492-8506.
This paper presents a compact-sized haptic device based on a cable-driven parallel robot (CDPR) mechanism for teleoperation. CDPRs characteristically have large workspaces and lightweight actuators. An intuitive and user-friendly remote control has not yet been achieved, owing to the unfamiliar multiple-cable configuration of CDPRs. To address this, we constructed a portable compact-sized CDPR with the same configuration as that of a larger fully constrained slave CDPR. The haptic device is controlled by an admittance control for stiffness adjustment and implemented in an embedded microprocessor-based controller for easy installation on an operator’s desk. To validate the performance of the device, we constructed an experimental teleoperation setup by using the prototyped portable CDPR as a master and larger-size CDPR as a slave robot. Experimental results showed that a human operator can successfully control the master device from a remote site and synchronized motion between the master and slave device was performed. Moreover, the user-friendly teleoperation could intuitively address situations at a remote site and provide an operator with realistic force during the motion of the slave CDPR.
Jae-Hyun Park; Min-Cheol Kim; Ralf Böhl; Sebastian Gommel; Eui-Sun Kim; Eunpyo Choi; Jong-Oh Park; Chang-Sei Kim. A Portable Intuitive Haptic Device on a Desk for User-Friendly Teleoperation of a Cable-Driven Parallel Robot. Applied Sciences 2021, 11, 3823 .
AMA StyleJae-Hyun Park, Min-Cheol Kim, Ralf Böhl, Sebastian Gommel, Eui-Sun Kim, Eunpyo Choi, Jong-Oh Park, Chang-Sei Kim. A Portable Intuitive Haptic Device on a Desk for User-Friendly Teleoperation of a Cable-Driven Parallel Robot. Applied Sciences. 2021; 11 (9):3823.
Chicago/Turabian StyleJae-Hyun Park; Min-Cheol Kim; Ralf Böhl; Sebastian Gommel; Eui-Sun Kim; Eunpyo Choi; Jong-Oh Park; Chang-Sei Kim. 2021. "A Portable Intuitive Haptic Device on a Desk for User-Friendly Teleoperation of a Cable-Driven Parallel Robot." Applied Sciences 11, no. 9: 3823.
Microscale and nanoscale robots, frequently referred to as future cargo systems for targeted drug delivery, can effectively convert magnetic energy into locomotion. However, navigating and imaging them within a complex colloidal vascular system at a clinical scale is exigent. Hence, a more precise and enhanced hybrid control navigation and imaging system is necessary. Magnetic particle imaging (MPI) has been successfully applied to visualize the ensemble of superparamagnetic nanoparticles (MNPs) with high temporal sensitivity. MPI uses the concept of field-free point (FFP) mechanism in the principal magnetic field. The gradient magnetic field (|∇B|) of MPI scanners can generate sufficient magnetic force in MNPs; hence, it has been recently used to navigate nanosized particles and micron-sized swimmers. In this article, we present a simulation analysis of the optimized navigation of an ensemble of microsized polymer MNP-based drug carriers in blood vessels. Initially, an ideal two-dimensional FFP case is employed for the basic optimization of the FFP position to achieve efficient navigation. Thereafter, a nine-coil electromagnetic actuation simulation system is developed to generate and manipulate the FFP position and |∇B|. Under certain vessel and fluid conditions, the particle trajectories of different ferromagnetic polymer ratios and |∇B| were compared to optimize the FFP position.
Saqib Sharif; Kim Nguyen; Doyeon Bang; Jong-Oh Park; Eunpyo Choi. Optimization of Field-Free Point Position, Gradient Field and Ferromagnetic Polymer Ratio for Enhanced Navigation of Magnetically Controlled Polymer-Based Microrobots in Blood Vessel. Micromachines 2021, 12, 424 .
AMA StyleSaqib Sharif, Kim Nguyen, Doyeon Bang, Jong-Oh Park, Eunpyo Choi. Optimization of Field-Free Point Position, Gradient Field and Ferromagnetic Polymer Ratio for Enhanced Navigation of Magnetically Controlled Polymer-Based Microrobots in Blood Vessel. Micromachines. 2021; 12 (4):424.
Chicago/Turabian StyleSaqib Sharif; Kim Nguyen; Doyeon Bang; Jong-Oh Park; Eunpyo Choi. 2021. "Optimization of Field-Free Point Position, Gradient Field and Ferromagnetic Polymer Ratio for Enhanced Navigation of Magnetically Controlled Polymer-Based Microrobots in Blood Vessel." Micromachines 12, no. 4: 424.
A cylindrical shaped marine invertebrate ascidian has muscle fibers surrounding its body, which induce the contraction motion when the animal senses the external stimuli. As inspired by its cylindrical shape and the contraction motion of the ascidian, we introduce a soft robot that resembles this water animal. In this letter, we first discuss the design of the robot that can be magnetically actuated and create different motions due to different magnetic moments for each segment of the robot. The crawling motion of the robot is presented with a sinusoidal waveform of the magnetic field and we demonstrate the utility of our bio-inspired soft robot for transporting a millimeter-sized object and releasing a drug in a specific location.
Shirong Zheng; Tongil Park; Manh Cuong Hoang; Gwangjun Go; Chang-Sei Kim; Jong-Oh Park; Eunpyo Choi; Ayoung Hong. Ascidian-Inspired Soft Robots That Can Crawl, Tumble, and Pick-and-Place Objects. IEEE Robotics and Automation Letters 2021, 6, 1722 -1728.
AMA StyleShirong Zheng, Tongil Park, Manh Cuong Hoang, Gwangjun Go, Chang-Sei Kim, Jong-Oh Park, Eunpyo Choi, Ayoung Hong. Ascidian-Inspired Soft Robots That Can Crawl, Tumble, and Pick-and-Place Objects. IEEE Robotics and Automation Letters. 2021; 6 (2):1722-1728.
Chicago/Turabian StyleShirong Zheng; Tongil Park; Manh Cuong Hoang; Gwangjun Go; Chang-Sei Kim; Jong-Oh Park; Eunpyo Choi; Ayoung Hong. 2021. "Ascidian-Inspired Soft Robots That Can Crawl, Tumble, and Pick-and-Place Objects." IEEE Robotics and Automation Letters 6, no. 2: 1722-1728.
The ability to manipulate therapeutic agents in fluids is of interest to improve the efficiency of targeted drug delivery. Ultrasonic manipulation has great potential in the field of therapeutic applications as it can trap and manipulate micro-scale objects. Recently, several methods of ultrasonic manipulation have been studied through standing wave, traveling wave, and acoustic streaming. Among them, the traveling wave based ultrasonic manipulation is showing more advantage for in vivo environments. In this paper, we present a novel ultrasonic transducer (UT) array with a hemispherical arrangement that generates active traveling waves with phase modulation to manipulate a micromotor in water. The feasibility of the method could be demonstrated by in vitro and ex vivo experiments conducted using a UT array with 16 transducers operating at 1 MHz. The phase of each transducer was controlled independently for generating a twin trap and manipulation of a micromotor in 3D space. This study shows that the ultrasonic manipulation device using active traveling waves is a versatile tool that can be used for precise manipulation of a micromotor inserted in a human body and targeted for drug delivery.
Hiep Cao; Daewon Jung; Han-Sol Lee; Gwangjoon Go; Minghui Nan; Eunpyo Choi; Chang-Sei Kim; Jong-Oh Park; Byungjeon Kang. Micromotor Manipulation Using Ultrasonic Active Traveling Waves. Micromachines 2021, 12, 192 .
AMA StyleHiep Cao, Daewon Jung, Han-Sol Lee, Gwangjoon Go, Minghui Nan, Eunpyo Choi, Chang-Sei Kim, Jong-Oh Park, Byungjeon Kang. Micromotor Manipulation Using Ultrasonic Active Traveling Waves. Micromachines. 2021; 12 (2):192.
Chicago/Turabian StyleHiep Cao; Daewon Jung; Han-Sol Lee; Gwangjoon Go; Minghui Nan; Eunpyo Choi; Chang-Sei Kim; Jong-Oh Park; Byungjeon Kang. 2021. "Micromotor Manipulation Using Ultrasonic Active Traveling Waves." Micromachines 12, no. 2: 192.
Targeted drug delivery using a microrobot is a promising technique capable of overcoming the limitations of conventional chemotherapy that relies on body circulation. However, most studies of microrobots used for drug delivery have only demonstrated simple mobility rather than precise targeting methods and prove the possibility of biodegradation of implanted microrobots after drug delivery. In this study, magnetically guided self‐rolled microrobot that enables autonomous navigation‐based targeted drug delivery, real‐time X‐ray imaging, and microrobot retrieval is proposed. The microrobot, composed of a self‐rolled body that is printed using focused light and a surface with magnetic nanoparticles attached, demonstrates the loading of doxorubicin and an X‐ray contrast agent for cancer therapy and X‐ray imaging. The microrobot is precisely mobilized to the lesion site through automated targeting using magnetic field control of an electromagnetic actuation system under real‐time X‐ray imaging. The photothermal effect using near‐infrared light reveals rapid drug release of the microrobot located at the lesion site. After drug delivery, the microrobot is recovered without potential toxicity by implantation or degradation using a magnetic‐field‐switchable coiled catheter. This microrobotic approach using automated control method of the therapeutic agents‐loaded microrobot has potential use in precise localized drug delivery systems.
Kim Tien Nguyen; Gwangjun Go; Zhen Jin; Bobby Aditya Darmawan; Ami Yoo; Seokjae Kim; Minghui Nan; Sang Bong Lee; Byungjeon Kang; Chang‐Sei Kim; Hao Li; Doyeon Bang; Jong‐Oh Park; Eunpyo Choi. A Magnetically Guided Self‐Rolled Microrobot for Targeted Drug Delivery, Real‐Time X‐Ray Imaging, and Microrobot Retrieval. Advanced Healthcare Materials 2021, 10, 2001681 .
AMA StyleKim Tien Nguyen, Gwangjun Go, Zhen Jin, Bobby Aditya Darmawan, Ami Yoo, Seokjae Kim, Minghui Nan, Sang Bong Lee, Byungjeon Kang, Chang‐Sei Kim, Hao Li, Doyeon Bang, Jong‐Oh Park, Eunpyo Choi. A Magnetically Guided Self‐Rolled Microrobot for Targeted Drug Delivery, Real‐Time X‐Ray Imaging, and Microrobot Retrieval. Advanced Healthcare Materials. 2021; 10 (6):2001681.
Chicago/Turabian StyleKim Tien Nguyen; Gwangjun Go; Zhen Jin; Bobby Aditya Darmawan; Ami Yoo; Seokjae Kim; Minghui Nan; Sang Bong Lee; Byungjeon Kang; Chang‐Sei Kim; Hao Li; Doyeon Bang; Jong‐Oh Park; Eunpyo Choi. 2021. "A Magnetically Guided Self‐Rolled Microrobot for Targeted Drug Delivery, Real‐Time X‐Ray Imaging, and Microrobot Retrieval." Advanced Healthcare Materials 10, no. 6: 2001681.
Objective: For the revascularization in small vessels such as coronary arteries, we present a guide-wired helical microrobot mimicking the corkscrew motion for mechanical atherectomy that enables autonomous therapeutics and minimizing the radiation exposure to clinicians. Methods: The microrobot is fabricated with a spherical joint and a guidewire. A previously developed external electromagnetic manipulation system capable of high power and frequency is incorporated and an autonomous guidance motion control including driving and steering is implemented in the prototype. We tested the validity of our approach in animal experiments under clinical settings. For the in vivo test, artificial thrombus was fabricated and placed in a small vessel and atherectomy procedures were conducted. Results: The devised approach enables us to navigate the helical robot to the target area and successfully unclog the thrombosis in rat models in vivo. Conclusion: This technology overcomes several limitations associated with a small vessel environment and promises to advance medical microrobotics for real clinical applications while achieving intact operation and minimizing radiation exposures to clinicians. Significance: Advanced microrobot based on multi-discipline technology could be validated in vivo for the first time and that may foster the microrobot application at clinical sites.
Kim Tien Nguyen; Seok-Jae Kim; Huyn-Ki Min; Manh Cuong Hoang; Gwangjun Go; Byungjeon Kang; Jayoung Kim; Eunpyo Choi; Ayoung Hong; Jong-Oh Park; Chang-Sei Kim. Guide-Wired Helical Microrobot for Percutaneous Revascularization in Chronic Total Occlusion in-Vivo Validation. IEEE Transactions on Biomedical Engineering 2020, 68, 2490 -2498.
AMA StyleKim Tien Nguyen, Seok-Jae Kim, Huyn-Ki Min, Manh Cuong Hoang, Gwangjun Go, Byungjeon Kang, Jayoung Kim, Eunpyo Choi, Ayoung Hong, Jong-Oh Park, Chang-Sei Kim. Guide-Wired Helical Microrobot for Percutaneous Revascularization in Chronic Total Occlusion in-Vivo Validation. IEEE Transactions on Biomedical Engineering. 2020; 68 (8):2490-2498.
Chicago/Turabian StyleKim Tien Nguyen; Seok-Jae Kim; Huyn-Ki Min; Manh Cuong Hoang; Gwangjun Go; Byungjeon Kang; Jayoung Kim; Eunpyo Choi; Ayoung Hong; Jong-Oh Park; Chang-Sei Kim. 2020. "Guide-Wired Helical Microrobot for Percutaneous Revascularization in Chronic Total Occlusion in-Vivo Validation." IEEE Transactions on Biomedical Engineering 68, no. 8: 2490-2498.
The development of ultralow voltage high‐performance bioartificial muscles with large bending strain, fast response time, and excellent actuation durability is highly desirable for promising applications such as soft robotics, active biomedical devices, flexible haptic displays, and wearable electronics. Herein, a novel high‐performance low‐priced bioartificial muscle based on functional carboxylated bacterial cellulose (FCBC) and polypyrrole (PPy) nanoparticles is reported, exhibiting a large bending strain of 0.93%, long actuated bending durability (96% retention for 5 h) under an ultralow harmonic input of 0.5 V, broad frequency bandwidth up to 10 Hz, fast response time (≈4 s) in DC responses, high energy density (6.81 KJ m−3), and high power density (5.11 KW m−3), all of which mainly stem from its high surface area and porosity, large specific capacitance, tuned mechanical properties, and strong ionic interactions of cations and anions in ionic liquid with FCBC and PPy nanoparticles. More importantly, bioinspired applications such as the grapple robot, bionic medical stent, bionic flower, and wings‐vibrating have been realized. These successful demonstrations offer a viable means for developing high‐performance bioartificial muscles for next‐generation soft bioelectronics including bioinspired robotics, biomedical microdevices, and wearable electronics.
Fan Wang; Qinchuan Li; Jong‐Oh Park; Shaohui Zheng; Eunpyo Choi. Ultralow Voltage High‐Performance Bioartificial Muscles Based on Ionically Crosslinked Polypyrrole‐Coated Functional Carboxylated Bacterial Cellulose for Soft Robots. Advanced Functional Materials 2020, 31, 1 .
AMA StyleFan Wang, Qinchuan Li, Jong‐Oh Park, Shaohui Zheng, Eunpyo Choi. Ultralow Voltage High‐Performance Bioartificial Muscles Based on Ionically Crosslinked Polypyrrole‐Coated Functional Carboxylated Bacterial Cellulose for Soft Robots. Advanced Functional Materials. 2020; 31 (13):1.
Chicago/Turabian StyleFan Wang; Qinchuan Li; Jong‐Oh Park; Shaohui Zheng; Eunpyo Choi. 2020. "Ultralow Voltage High‐Performance Bioartificial Muscles Based on Ionically Crosslinked Polypyrrole‐Coated Functional Carboxylated Bacterial Cellulose for Soft Robots." Advanced Functional Materials 31, no. 13: 1.
We described a magnetic chitosan microscaffold tailored for applications requiring high biocompatibility, biodegradability, and monitoring by real-time imaging. Such magnetic microscaffolds exhibit adjustable pores and sizes depending on the target application and provide various functions such as magnetic actuation and enhanced cell adhesion using biomaterial-based magnetic particles. Subsequently, we fabricated the magnetic chitosan microscaffolds with optimized shape and pore properties to specific target diseases. As a versatile tool, the capability of the developed microscaffold was demonstrated through in vitro laboratory tasks and in vivo therapeutic applications for liver cancer therapy and knee cartilage regeneration. We anticipate that the optimal design and fabrication of the presented microscaffold will advance the technology of biopolymer-based microscaffolds and micro/nanorobots.
Gwangjun Go; Ami Yoo; Hyeong-Woo Song; Hyun-Ki Min; Shirong Zheng; Kim Tien Nguyen; Seokjae Kim; Byungjeon Kang; Ayoung Hong; Chang-Sei Kim; Jong-Oh Park; Eunpyo Choi. Multifunctional Biodegradable Microrobot with Programmable Morphology for Biomedical Applications. ACS Nano 2020, 15, 1059 -1076.
AMA StyleGwangjun Go, Ami Yoo, Hyeong-Woo Song, Hyun-Ki Min, Shirong Zheng, Kim Tien Nguyen, Seokjae Kim, Byungjeon Kang, Ayoung Hong, Chang-Sei Kim, Jong-Oh Park, Eunpyo Choi. Multifunctional Biodegradable Microrobot with Programmable Morphology for Biomedical Applications. ACS Nano. 2020; 15 (1):1059-1076.
Chicago/Turabian StyleGwangjun Go; Ami Yoo; Hyeong-Woo Song; Hyun-Ki Min; Shirong Zheng; Kim Tien Nguyen; Seokjae Kim; Byungjeon Kang; Ayoung Hong; Chang-Sei Kim; Jong-Oh Park; Eunpyo Choi. 2020. "Multifunctional Biodegradable Microrobot with Programmable Morphology for Biomedical Applications." ACS Nano 15, no. 1: 1059-1076.
Targeted drug delivery (TDD) based on magnetic nanoparticles (MNPs) and external magnetic actuation is a promising drug delivery technology compared to conventional treatments usually utilized in cancer therapy. However, the implementation of a TDD system at a clinical site based on considerations for the actual size of the human body requires a simplified structure capable of both external actuation and localization. To address these requirements, we propose a novel approach to localize drug carriers containing MNPs by manipulating the field-free point (FFP) mechanism in the principal magnetic field. To this end, we devise a versatile electromagnetic actuation (EMA) system for FFP generation based on four coils affixed to a movable frame. By the Biot–Savart law, the FFP can be manipulated by appropriately controlling the gradient field strength at the target area using the EMA system. Further, weighted-norm solutions are utilized to correct the positions of FFP to improve the accuracy of FFP displacement in the region of interest (ROI). As MNPs, ferrofluid is used to experiment with 2D and 3D localizations in a blocked phantom placed in the designed ROI. The resultant root mean square error of the localizations is observed to be approximately 1.4 mm in the 2D case and 1.6 mm in the 3D case. Further, the proposed movable EMA is verified to be capable of simultaneously scanning multiple points as well as the actuation and imaging of MNPs. Based on the success of the experiments in this study, further research is intended to be conducted in scale-up system development to design precise TDD systems at clinical sites.
Chan Kim; Jayoung Kim; Jong-Oh Park; Eunpyo Choi; Chang-Sei Kim. Localization and Actuation for MNPs Based on Magnetic Field-Free Point: Feasibility of Movable Electromagnetic Actuations. Micromachines 2020, 11, 1020 .
AMA StyleChan Kim, Jayoung Kim, Jong-Oh Park, Eunpyo Choi, Chang-Sei Kim. Localization and Actuation for MNPs Based on Magnetic Field-Free Point: Feasibility of Movable Electromagnetic Actuations. Micromachines. 2020; 11 (11):1020.
Chicago/Turabian StyleChan Kim; Jayoung Kim; Jong-Oh Park; Eunpyo Choi; Chang-Sei Kim. 2020. "Localization and Actuation for MNPs Based on Magnetic Field-Free Point: Feasibility of Movable Electromagnetic Actuations." Micromachines 11, no. 11: 1020.
Untethered small-scale soft robots have been widely researched because they can be employed to perform wireless procedures via natural orifices in the human body, or other minimally invasive operations. Nevertheless, achieving untethered robotic motion remains challenging owing to the lack of an effective wireless actuation mechanism. To overcome this limitation, we propose a magnetically actuated walking soft robot based on paper and a chained magnetic-microparticle-embedded polymer actuator. The magnetic polymer actuator was prepared by combining Fe3O4 magnetic particles (MPs, diameter of ~50 nm) and silicon that are affected by a magnetic field; thereafter, the magnetic properties were quantified to achieve proper force and optimized according to the mass ratio, viscosity, and rotational speed of a spin coater. The fabricated polymer was utilized as a soft robot actuator that can be controlled using an external magnetic field, and paper was employed to construct the robot body with legs to achieve walking motion. To confirm the feasibility of the designed robot, the operating capability of the robot was analyzed through finite element simulation, and a walking experiment was conducted using electromagnetic actuation. The soft robot could be moved by varying the magnetic flux density and on–off state, and it demonstrated a maximum moving speed of 0.77 mm/s. Further studies on the proposed soft walking robot may advance the development of small-scale robots with diagnostic and therapeutic functionalities for application in biomedical fields.
Han-Sol Lee; Yong-Uk Jeon; In-Seong Lee; Jin-Yong Jeong; Manh Hoang; Ayoung Hong; Eunpyo Choi; Jong-Oh Park; Chang-Sei Kim. Wireless Walking Paper Robot Driven by Magnetic Polymer Actuator. Actuators 2020, 9, 109 .
AMA StyleHan-Sol Lee, Yong-Uk Jeon, In-Seong Lee, Jin-Yong Jeong, Manh Hoang, Ayoung Hong, Eunpyo Choi, Jong-Oh Park, Chang-Sei Kim. Wireless Walking Paper Robot Driven by Magnetic Polymer Actuator. Actuators. 2020; 9 (4):109.
Chicago/Turabian StyleHan-Sol Lee; Yong-Uk Jeon; In-Seong Lee; Jin-Yong Jeong; Manh Hoang; Ayoung Hong; Eunpyo Choi; Jong-Oh Park; Chang-Sei Kim. 2020. "Wireless Walking Paper Robot Driven by Magnetic Polymer Actuator." Actuators 9, no. 4: 109.
Recently an active locomotive capsule endoscope (CE) for diagnosis and treatment in the digestive system has been widely studied. However, real-time localization to achieve precise feedback control and record suspicious positioning in the intestine is still challenging owing to the limitation of capsule size, relatively large diagnostic volume, and compatibility of other devices in clinical site. To address this issue, we present a novel robotic localization sensing methodology based on the kinematics of a planar cable driven parallel robot (CDPR) and measurements of the quasistatic magnetic field of a Hall effect sensor (HES) array. The arrangement of HES and the Levenberg-Marquardt (LM) algorithm are applied to estimate the position of the permanent magnet (PM) in the CE, and the planar CDPR is incorporated to follow the PM in the CE. By tracking control of the planar CDPR, the position of PM in any arbitrary position can be obtained through robot forward kinematics with respect to the global coordinates at the bedside. The experimental results show that the root mean square error (RMSE) for the estimated position value of PM was less than 1.13 mm in the X, Y, and Z directions and less than 1.14° in the θ and φ orientation, where the sensing space could be extended to ±70 mm for the given 34 × 34 mm2 HES array and the average moving distance in the Z-direction is 40 ± 2.42 mm. The proposed method of the robotic sensing with HES and CDPR may advance the sensing space expansion technology by utilizing the provided single sensor module of limited sensible volume.
Min-Cheol Kim; Eui-Sun Kim; Jong-Oh Park; Eunpyo Choi; Chang-Sei Kim. Robotic Localization Based on Planar Cable Robot and Hall Sensor Array Applied to Magnetic Capsule Endoscope. Sensors 2020, 20, 5728 .
AMA StyleMin-Cheol Kim, Eui-Sun Kim, Jong-Oh Park, Eunpyo Choi, Chang-Sei Kim. Robotic Localization Based on Planar Cable Robot and Hall Sensor Array Applied to Magnetic Capsule Endoscope. Sensors. 2020; 20 (20):5728.
Chicago/Turabian StyleMin-Cheol Kim; Eui-Sun Kim; Jong-Oh Park; Eunpyo Choi; Chang-Sei Kim. 2020. "Robotic Localization Based on Planar Cable Robot and Hall Sensor Array Applied to Magnetic Capsule Endoscope." Sensors 20, no. 20: 5728.
The concept of an active drug delivery and controlled drug release using microrobot system has attracted attention over the past decade. However, developing these microrobot system is hindered by the low drug release rate upon external stimuli, such as an alternating magnetic field or light, with a long stimulation period (>40% release upon 10 min stimulation). This study evaluated using self-rolled helical microrobots to provide a controlled drug delivery system that uses magnetic manipulation and provides for highly efficient drug release. The rapid and simple fabrication of helical microrobots that change shape upon exposure to protic/aprotic stimuli was demonstrated using a single-layer self-folding technique. The self-folded helical microrobots navigated in the desired direction using a rotating magnetic field produced by an electromagnetic actuator. After arrival at the target location, non-covalently bonded anti-cancer drugs were released during a short period of ultrasound stimulation. The results demonstrate that, with 1 min of ultrasound stimulation, more than 90% of drug release was achieved. This efficient drug release system could enable the practical application of a microrobot-based drug delivery system.
Bobby Aditya Darmawan; Sang Bong Lee; Van Du Nguyen; Gwangjun Go; Kim Tien Nguyen; Han-Sol Lee; Minghui Nan; Ayoung Hong; Chang-Sei Kim; Hao Li; Doyeon Bang; Jong-Oh Park; Eunpyo Choi. Self-folded microrobot for active drug delivery and rapid ultrasound-triggered drug release. Sensors and Actuators B: Chemical 2020, 324, 128752 .
AMA StyleBobby Aditya Darmawan, Sang Bong Lee, Van Du Nguyen, Gwangjun Go, Kim Tien Nguyen, Han-Sol Lee, Minghui Nan, Ayoung Hong, Chang-Sei Kim, Hao Li, Doyeon Bang, Jong-Oh Park, Eunpyo Choi. Self-folded microrobot for active drug delivery and rapid ultrasound-triggered drug release. Sensors and Actuators B: Chemical. 2020; 324 ():128752.
Chicago/Turabian StyleBobby Aditya Darmawan; Sang Bong Lee; Van Du Nguyen; Gwangjun Go; Kim Tien Nguyen; Han-Sol Lee; Minghui Nan; Ayoung Hong; Chang-Sei Kim; Hao Li; Doyeon Bang; Jong-Oh Park; Eunpyo Choi. 2020. "Self-folded microrobot for active drug delivery and rapid ultrasound-triggered drug release." Sensors and Actuators B: Chemical 324, no. : 128752.
There are challenges in developing practically viable biopolymer-based actuators with ecofriendly, biocompatible, and biodegradable functionalities. Therefore, we propose a cellulose acetate (CA)-based ecofriendly soft-ionic networking actuator consisting of multifunctional additive polyvinylidene difluoride (PVDF), highly conductive ammonia-functionalized graphene nanoplatelets (AFGNPs), ionic liquids (IL), and flexible conducting polymer poly(3,4-ethylenedioxuthiopene)-polystyrene sulfonate (PEDOT:PSS) as an electrode. The proposed actuator exhibits a large bending displacement and short response time in an open-air environment, resulting from its enhanced electro-chemo-mechanical properties and strong ionic and interfacial interactions. In comparison with CA/PVDF-IL actuator, the CA/PVDF–IL–AFGNPs actuator demonstrates a considerably increased IL uptake and ion-exchange capacity of up to 71.04% and 300.6%, respectively, and an increase in the specific capacitance by over 3.64 times, which lead to bending actuation performances 2.21 and 1.87 times greater, respectively, under AC (4 V) and DC (4 V). Moreover, we demonstrate that a CA/PVDF–IL–AFGNPs actuator with a hierarchical structure shows values that are 1.32, 1.5, and 1.74 times larger than those of a planar actuator in DC (4 V), AC (3 V), and blocking force (4 V), respectively. The developed high-performance CA/PVDF–AFGNPs and the hierarchical surface texture of the patterned CA/PVDF–IL–AFGNPs actuators present these extraordinary achievements together with environmentally friendly materials, a low driving voltage, easy manufacturing, and high actuation performances. Therefore, they can be candidates for human-friendly products (e.g., biomedical devices, bioinspired robots, and soft haptic devices).
Minghui Nan; Doyeon Bang; Shirong Zheng; Gwangjun Go; Bobby Aditya Darmawan; Seokjae Kim; Hao Li; Chang-Sei Kim; Ayoung Hong; Fan Wang; Jong-Oh Park; Eunpyo Choi. High-performance biocompatible nanobiocomposite artificial muscles based on ammonia-functionalized graphene nanoplatelets–cellulose acetate combined with PVDF. Sensors and Actuators B: Chemical 2020, 323, 128709 .
AMA StyleMinghui Nan, Doyeon Bang, Shirong Zheng, Gwangjun Go, Bobby Aditya Darmawan, Seokjae Kim, Hao Li, Chang-Sei Kim, Ayoung Hong, Fan Wang, Jong-Oh Park, Eunpyo Choi. High-performance biocompatible nanobiocomposite artificial muscles based on ammonia-functionalized graphene nanoplatelets–cellulose acetate combined with PVDF. Sensors and Actuators B: Chemical. 2020; 323 ():128709.
Chicago/Turabian StyleMinghui Nan; Doyeon Bang; Shirong Zheng; Gwangjun Go; Bobby Aditya Darmawan; Seokjae Kim; Hao Li; Chang-Sei Kim; Ayoung Hong; Fan Wang; Jong-Oh Park; Eunpyo Choi. 2020. "High-performance biocompatible nanobiocomposite artificial muscles based on ammonia-functionalized graphene nanoplatelets–cellulose acetate combined with PVDF." Sensors and Actuators B: Chemical 323, no. : 128709.
Recently, significant research efforts have been devoted toward the development of magnetically controllable drug delivery systems, however, drug fixation after targeting remains a challenge hindering long-term therapeutic efficacy. To overcome this issue, we present a wearable therapeutic fixation device for fixing magnetically controllable therapeutic agent carriers (MCTACs) at defect sites and its application to cartilage repair using stem cell therapeutics. The developed device comprises an array of permanent magnets based on the Halbach array principle and a wearable band capable of wrapping the target body. The design of the permanent magnet array, in terms of the number of magnets and array configuration, was determined through univariate search optimization and 3D simulation. The device was fabricated for a given rat model and yielded a strong magnetic flux density (exceeding 40 mT) in the region of interest that was capable of fixing the MCTAC at the desired defect site. Through in-vitro and in-vivo experiments, we successfully demonstrated that MCTACs, both a stem cell spheroid and a micro-scaffold for cartilage repair, could be immobilized at defect sites. This research is expected to advance precise drug delivery technology based on MCTACs, enabling subject-specific routine life therapeutics. Further studies involving the proposed wearable fixation device will be conducted considering prognostics under actual clinical settings.
Kyungmin Lee; Gwangjun Go; Ami Yoo; Byungjeon Kang; Eunpyo Choi; Jong-Oh Park; Chang-Sei Kim. Wearable Fixation Device for a Magnetically Controllable Therapeutic Agent Carrier: Application to Cartilage Repair. Pharmaceutics 2020, 12, 593 .
AMA StyleKyungmin Lee, Gwangjun Go, Ami Yoo, Byungjeon Kang, Eunpyo Choi, Jong-Oh Park, Chang-Sei Kim. Wearable Fixation Device for a Magnetically Controllable Therapeutic Agent Carrier: Application to Cartilage Repair. Pharmaceutics. 2020; 12 (6):593.
Chicago/Turabian StyleKyungmin Lee; Gwangjun Go; Ami Yoo; Byungjeon Kang; Eunpyo Choi; Jong-Oh Park; Chang-Sei Kim. 2020. "Wearable Fixation Device for a Magnetically Controllable Therapeutic Agent Carrier: Application to Cartilage Repair." Pharmaceutics 12, no. 6: 593.
Although great efforts have been undertaken to develop a nanoparticle-based drug delivery system (DDS) for the treatment of solid tumors, the therapeutic outcomes are still limited. Immune cells, which possess an intrinsic ability to phagocytose nanoparticles and are recruited by tumors, can be exploited to deliver nanotherapeutics deep inside the tumors. Photothermal therapy using near-infrared light is a promising non-invasive approach for solid tumor ablation, especially when combined with chemotherapy. In this study, we designed and evaluated a macrophage-based, multiple-nanotherapeutics DDS, involving the phagocytosis by macrophages of both small-sized gold nanorods and anticancer drug-containing nanoliposomes. The aim was to treat solid tumors, utilizing the tumor-infiltrating properties of macrophages with synergistic photothermal-chemotherapy. Using a 3D cancer spheroid solid tumor model, we show that tumor penetration and coverage by the nanoparticles were both markedly enhanced when the macrophages were used, compared to when using the nanoparticles only. In addition, in vivo experiments involving both local and systemic administrations in breast tumor-bearing mice demonstrate that the proposed DDS can effectively target and kill the tumors, especially when combined with chemo-photothermal therapy. Consequently, this immune cell-based theranostic strategy may represent a potentially important advancement in the treatment of solid tumors.
Van Du Nguyen; Hyun-Ki Min; Deok-Ho Kim; Chang-Sei Kim; Jiwon Han; Jong-Oh Park; Eunpyo Choi. Macrophage-Mediated Delivery of Multifunctional Nanotherapeutics for Synergistic Chemo–Photothermal Therapy of Solid Tumors. ACS Applied Materials & Interfaces 2020, 12, 10130 -10141.
AMA StyleVan Du Nguyen, Hyun-Ki Min, Deok-Ho Kim, Chang-Sei Kim, Jiwon Han, Jong-Oh Park, Eunpyo Choi. Macrophage-Mediated Delivery of Multifunctional Nanotherapeutics for Synergistic Chemo–Photothermal Therapy of Solid Tumors. ACS Applied Materials & Interfaces. 2020; 12 (9):10130-10141.
Chicago/Turabian StyleVan Du Nguyen; Hyun-Ki Min; Deok-Ho Kim; Chang-Sei Kim; Jiwon Han; Jong-Oh Park; Eunpyo Choi. 2020. "Macrophage-Mediated Delivery of Multifunctional Nanotherapeutics for Synergistic Chemo–Photothermal Therapy of Solid Tumors." ACS Applied Materials & Interfaces 12, no. 9: 10130-10141.
Targeted cell delivery by a magnetically actuated microrobot with a porous structure is a promising technique to enhance the low targeting efficiency of mesenchymal stem cell (MSC) in tissue regeneration. However, the relevant research performed to date is only in its proof-of-concept stage. To use the microrobot in a clinical stage, biocompatibility and biodegradation materials should be considered in the microrobot, and its efficacy needs to be verified using an in vivo model. In this study, we propose a human adipose–derived MSC–based medical microrobot system for knee cartilage regeneration and present an in vivo trial to verify the efficacy of the microrobot using the cartilage defect model. The microrobot system consists of a microrobot body capable of supporting MSCs, an electromagnetic actuation system for three-dimensional targeting of the microrobot, and a magnet for fixation of the microrobot to the damaged cartilage. Each component was designed and fabricated considering the accessibility of the patient and medical staff, as well as clinical safety. The efficacy of the microrobot system was then assessed in the cartilage defect model of rabbit knee with the aim to obtain clinical trial approval.
Gwangjun Go; Sin-Gu Jeong; Ami Yoo; Jiwon Han; Byungjeon Kang; Seokjae Kim; Kim Tien Nguyen; Zhen Jin; Chang-Sei Kim; Yu Ri Seo; Ju Yeon Kang; Ju Yong Na; Eun Kyoo Song; Yongyeon Jeong; Jong Keun Seon; Jong-Oh Park; Eunpyo Choi. Human adipose–derived mesenchymal stem cell–based medical microrobot system for knee cartilage regeneration in vivo. Science Robotics 2020, 5, eaay6626 .
AMA StyleGwangjun Go, Sin-Gu Jeong, Ami Yoo, Jiwon Han, Byungjeon Kang, Seokjae Kim, Kim Tien Nguyen, Zhen Jin, Chang-Sei Kim, Yu Ri Seo, Ju Yeon Kang, Ju Yong Na, Eun Kyoo Song, Yongyeon Jeong, Jong Keun Seon, Jong-Oh Park, Eunpyo Choi. Human adipose–derived mesenchymal stem cell–based medical microrobot system for knee cartilage regeneration in vivo. Science Robotics. 2020; 5 (38):eaay6626.
Chicago/Turabian StyleGwangjun Go; Sin-Gu Jeong; Ami Yoo; Jiwon Han; Byungjeon Kang; Seokjae Kim; Kim Tien Nguyen; Zhen Jin; Chang-Sei Kim; Yu Ri Seo; Ju Yeon Kang; Ju Yong Na; Eun Kyoo Song; Yongyeon Jeong; Jong Keun Seon; Jong-Oh Park; Eunpyo Choi. 2020. "Human adipose–derived mesenchymal stem cell–based medical microrobot system for knee cartilage regeneration in vivo." Science Robotics 5, no. 38: eaay6626.
Capsule endoscopes (CEs) have emerged as an advanced diagnostic technology for gastrointestinal diseases in recent decades. However, with regard to robotic motions, they require active movability and multi-functionalities for extensive, untethered, and precise clinical utilization. Herein, we present a novel wireless biopsy CE employing active five degree-of-freedom locomotion and a biopsy needle punching mechanism for the histological analysis of the intestinal tract. A medical biopsy punch is attached to a screw mechanism, which can be magnetically actuated to extrude and retract the biopsy tool, for tissue extraction. The external magnetic field from an electromagnetic actuation (EMA) system is utilized to actuate the screw mechanism and harvest biopsy tissue; therefore, the proposed system consumes no onboard energy of the CE. This design enables observation of the biopsy process through the capsule’s camera. A prototype with a diameter of 12 mm and length of 30 mm was fabricated with a medical biopsy punch having a diameter of 1.5 mm. Its performance was verified through numerical analysis, as well as in-vitro and ex-vivo experiments on porcine intestine. The CE could be moved to target lesions and obtain sufficient tissue samples for histological examination. The proposed biopsy CE mechanism utilizing punch biopsy and its wireless extraction–retraction technique can advance untethered intestinal endoscopic capsule technology at clinical sites.
Manh Cuong Hoang; Viet Ha Le; Kim Tien Nguyen; Van Du Nguyen; Jayoung Kim; Eunpyo Choi; Seungmin Bang; Byungjeon Kang; Jong-Oh Park; Chang-Sei Kim. A Robotic Biopsy Endoscope with Magnetic 5-DOF Locomotion and a Retractable Biopsy Punch. Micromachines 2020, 11, 98 .
AMA StyleManh Cuong Hoang, Viet Ha Le, Kim Tien Nguyen, Van Du Nguyen, Jayoung Kim, Eunpyo Choi, Seungmin Bang, Byungjeon Kang, Jong-Oh Park, Chang-Sei Kim. A Robotic Biopsy Endoscope with Magnetic 5-DOF Locomotion and a Retractable Biopsy Punch. Micromachines. 2020; 11 (1):98.
Chicago/Turabian StyleManh Cuong Hoang; Viet Ha Le; Kim Tien Nguyen; Van Du Nguyen; Jayoung Kim; Eunpyo Choi; Seungmin Bang; Byungjeon Kang; Jong-Oh Park; Chang-Sei Kim. 2020. "A Robotic Biopsy Endoscope with Magnetic 5-DOF Locomotion and a Retractable Biopsy Punch." Micromachines 11, no. 1: 98.