https://scholarworks.korea.ac.kr/kumedicine/handle/2020.sw.kumedicine/9 Sat, 04 Apr 2026 14:25:55 GMT 2026-04-04T14:25:55Z https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/80171 Title: Molecular Weight-Driven Tunable Hyaluronic Acid-Based Hydrogels Modulate Immune Polarization in Three-Dimensional Microenvironments Authors: Kim, Jaechang; Son, Inwoo; Evereux, Vesper; Subramanian, Vivekanandan; Kolpek, Daniel; Ogidi, James; Park, Seungman; Park, Yong doo; Park, Jonghyuck Abstract: Macrophages exhibit phenotypic plasticity that is strongly influenced by their surrounding microenvironment, including extracellular matrix (ECM) components. Hyaluronic acid (HA), a major glycosaminoglycan in ECM, has immunomodulatory effects that are highly dependent on its molecular weight (MW). However, most previous studies have been limited to two-dimensional (2D) culture systems, which were unable to accurately replicate the in vivo environment. In this study, we utilized a three-dimensional (3D) culture system based on HA-based hydrogels to better understand the MW-dependent immunomodulatory effects of HA on macrophages under more physiologically relevant conditions. Three different MWs of HA were chemically modified and cross-linked with PEG-SH4 to form hydrogels with distinct biophysical properties. Immortalized macrophages were encapsulated within these hydrogels and assessed for the expression of both pro-inflammatory and anti-inflammatory markers. Notably, hydrogels with high-MW HA significantly upregulated the expression of anti-inflammatory markers, indicating that the immunomodulatory effects of HA in 3D culture are affected by its biophysical characteristics. Our findings demonstrate the potential of HA-based hydrogels as customizable ECM-mimetic scaffolds for modulating immune responses in regenerative medicine applications. Sun, 01 Mar 2026 00:00:00 GMT https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/80171 2026-03-01T00:00:00Z https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/78807 Title: Three-dimensional magnetic torque stimulation enhances functional structural maturation in developing human cardiac organoids Authors: Shin, Tae-hoon; Noh, Ji-min; Choi, Seung-cheol; Song, Myeongjin; Kang, Myeongjin; Song, Myeonghwa; Heo, Ryeon; Jeon, Young-keul; Kim, Sungjoon; Kim, Seungjong; Lim, Dosun; Park, Yongdoo Abstract: Mechanical forces play a critical role in heart development by activating mechanotransduction pathways. However, applying forces to cardiac organoid models has significant challenges due to technical limitations. In this study, we applied mechanical forces to cardiac organoids with a magnetic torque stimulation (MTS) system using magnetized nanoparticles controlled by a magnetic levitation system. Torque was exerted on developing cardiac organoids within a uniform magnetic field generated by a rotating magnet system. Cardiac organoids exposed to torque showed spatial distribution of atrial and ventricle specific marker proteins such as MLC2v and MLC2a. Gene expression analysis revealed that torque-applied organoids exhibited upregulation of maturation-related genes such as TNNT2, GJA1, MYH7 , and KCNJ2 as well as vascular specific genes such as PECAM1, VWF, PDGFRB , and ACTA2 . Analysis of mechanotransduction-related genes and proteins indicated increased expression of Lamin A/C, ITGA5, ITGB3, and emerin. Elevated phosphorylation levels of FAK, cofilin, and MLC2 were also confirmed in response to the applied force. Our findings suggest that mechanical force application via MTS system can promote both maturation and vascularization of cardiac organoids by activating mechanotransduction pathways. Statement of significance Mechanical cues are key regulators of cardiac development, yet their role in organoid maturation remains underexplored. In this study, we introduce a Magnetic Torque Stimulation (MTS) system that delivers precisely controlled rotational forces to stem cell-derived cardiac organoids via surface-bound magnetic particles. Application of MTS significantly promoted cardiac differentiation, structural maturation, and neovascularization within the organoids in vitro. These effects are attributed to mechanotransductive modulation of key developmental signaling pathways. The MTS platform offers a robust strategy for investigating biomechanical regulation of cardiac organogenesis and holds translational potential for organoid-based disease modeling, drug discovery, and regenerative medicine. © 2025 Acta Materialia Inc. Mon, 01 Dec 2025 00:00:00 GMT https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/78807 2025-12-01T00:00:00Z https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/79115 Title: Convolutional neural networks-based early Parkinson’s disease classification using cycling data from a steerable indoor bicycle Authors: Kim, Yekwang; Kim, Jaewook; Kang, Seonghyun; Lee, Yeji; Moon, Juhui; Park, Jinwoo; Kim, Byung-jo; Kim, Seungjong Abstract: Parkinson’s disease (PD) is a neurodegenerative disorder that leads to a decline in functions that are directly related to quality of life, and it is vital to detect PD in the early stages. Currently, the diagnosis of PD relies on comprehensive assessment of medical history and clinical examination. However, it is difficult to capture short-term variations in the patient’s disability level during medical visitations, especially in its early stage. In this study we explore the feasibility of PD detection using a CNN model and a bicycle mounted on a specially designed bicycle platform. The bicycle platform, Ultiracer, allows for some lateral movement via steering in order to simulate outdoor cycling experiences. The bicycle is equipped with two 6-axis force-torque sensors, one in the headset spacer and the other in the seat post. The input data for the CNN model consist of 30 s of data recorded during cycling (force, moment, speed, and lateral movement) and tabular data comprising personal information (sex, age, height, and weight). The results from 29 PD patients and 36 healthy controls, suggest the proposed CNN model presented an accuracy of approximately 86% in classification based on the 5-fold cross validation. © The Author(s) 2025. Mon, 01 Dec 2025 00:00:00 GMT https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/79115 2025-12-01T00:00:00Z https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/77803 Title: EMG-Based Gait Speed Control of a Lower-limb Exoskeleton for Gait Rehabilitation: A Proof-of-Concept Study with Post-stroke Chronic Hemiparetic Patients Authors: Choi, Junhyuk; Kim, Hyungmin; Choi, Junho; Lee, Jong Min; Choi, Taejin; Kim, Seung-Jong; Chun, Min Ho Abstract: The purpose of this paper is to introduce an EMG-based real-time gait speed control algorithm embedded robot-assisted gait training (RAGT) system for gait rehabilitation of post-stroke hemiparetic patients and to verify its feasibility and safety. According to the previous researches, the gait speed of ongoing step is linearly proportional to the maximum value of Soleus electromyogram (EMG) waveform length (WL) in the prior gait cycle. This tendency was observed not only on healthy people or the nonparetic side leg of post-stroke hemiparetic patients, but also on the affected side leg. Therefore, we developed an algorithm that can control the gait speed according to the magnitude of Soleus EMG signal and embeded it to a lower-limb exoskeleton to design task-oriented RAGT to improve effectiveness of gait rehabilitation for hemipatic patients in subacute phase. Firstly, we applied it to post-stroke patients in chronic phase. A total of 30 patients were participated and divided into the following three groups: constant gait speed RAGT Group A, EMG-based gait speed-controlled RAGT Group B, and traditional gait training Group C. All subjects safely completed a total of 10 days of gait training protocol, approximately 30 min/day, 2-3 days apart. Gait performance was measured before and after the training. The result showed the EMG WL in Group B was significantly increased. In this study, we proposed a novel RAGT system with EMG-based gait speed feedback and verified. The results confirmed its applicability with safety and in future clinical research with patients who require gait rehabilitation after stroke. Sat, 01 Nov 2025 00:00:00 GMT https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/77803 2025-11-01T00:00:00Z