Byeong-Ju Kwon

Je U, et al. Investig Clin Urol. 2025 Jan;66(1):87-96. https://doi.org/10.4111/icu.20240289

SooYeon Lim, HyeonJu Jeong, Byeong-Ju Kwon. HIRA Research 2024;4:34-48. https://doi.org/10.52937/hira.24.4.1.e8

Purpose: As ISO 13485 was revised in 2016, the domestic GMP (Good Manufacturing Practice) system was also revised and implemented in 2019. However, there are many problems in the domestic medical device industry because most of the small and medium-sized enterprises lack human and material resources. Accordingly, this study was conducted to provide education programs for domestic medical device companies to induce information provision and improve the company's quality management ability.Methods: First, analyze existing education. Second, based on the revised GMP system, a survey paper was produced to investigate difficulties and problems experienced by companies. Third, a two-week survey was conducted on domestic medical device manufacturers, and a total of 77 companies responded to this survey. Fourth, educational program development was conducted based on the results of the survey.Results and Conclusion: The developed education program consists of a total of five sessions. In this study, the educational program developed by grasping the needs of the company through a survey consists of a total of five sessions. The first session consisted of theoretical education and the second to fifth sessions of practical education. Through the education program developed in this study, it is expected to contribute to the overall development of medical device quality by establishing a domestic medical device manufacturing environment that secures the safety and performance of domestic medical device companies.

HMSC source-specific behaviors in 3D NO gel represent EC-like differentiation of ADSCs and pericyte-like characteristics of BMSCs.

Systemic injection of a photosensitizer is a general method in photodynamic therapy, but it has complications due to the unintended systemic distribution and remnants of photosensitizers. This study focused on the possibility of suppressing luminal proliferative cells by excessive reactive oxygen species from locally delivered photosensitizer with biocompatible polyurethane, instead of the systemic injection method. We used human bladder cancer cells, hematoporphyrin as the photosensitizer, and polyurethane film as the photosensitizer-delivering container. The light source was a self-made LED (510 nm, 5 mW cm⁻²) system. The cancer cells were cultured on different doses of hematoporphyrin-containing polyurethane film and irradiated with LED for 15 minutes and 30 minutes each. After irradiating with LED and incubating for 24 hours, cell viability analysis, cell cycle analysis, apoptosis assay, intracellular and extracellular ROS generation study and western blot were performed. The cancer cell suppression effects of different concentrations of the locally delivered hematoporphyrin with PDT were compared. Apoptosis dominant cancer cell suppressions were shown to be hematoporphyrin dose-dependent. However, after irradiation, intracellular ROS amounts were similar in all the groups having different doses of hematoporphyrin, but these values were definitely higher than those in the control group. Excessive extracellular ROS from the intended, locally delivered photosensitizer for photodynamic treatment application had an inhibitory effect on luminal proliferative cancer cells. This method can be another possibility for PDT application on contactable or attachable lesions.

Osteoporosis is a disease characterized by low bone mass, most commonly caused by an increase in bone resorption that is not matched by sufficient bone formation. The most common complications of postmenopausal osteoporosis are bone-related defects and fractures. Fracture healing is a multifactorial bone regeneration process, influenced by both biological and mechanical factors related to age, osteoporosis and stability of the osteosynthesis. During the treatment of bone defects in osteoporotic conditions, imbalanced bone remodeling is the leading cause for implant failure. To overcome these problems, ethyl-2,5-dihydroxybenzoate (E-2,5-DHB), a drug that promotes bone formation and inhibits bone resorption, was used. E-2,5-DHB-incorporating titanium (Ti) implants using poly(lactic-co-glycolic acid) (PLGA) coating for local delivery of E-2,5-DHB were developed and the effects on bone healing of femoral defects were evaluated in an osteoporotic model. The release of E-2,5-DHB resulted in decreased bone resorption and increased bone formation around the implant. Thus, it was confirmed that, in the osteoporotic model, bone healing was increased and implant fixation was enhanced. These results suggested that E-2,5-DHB-coated Ti implants have great potential as an ultimate local drug delivery system for bone tissue scaffolds.

Stem cells are a promising cell source for regenerative medicine due to their differentiation and self‐renewal capacities. In the field of regenerative medicine and tissue engineering, a variety of biomedical technologies have been tested to improve proangiogenic activities of stem cells. However, their therapeutic effect is found to be limited in the clinic because of cell loss, senescence, and insufficient therapeutic activities. To address this type of issue, advanced techniques for biomaterial synthesis and fabrication have been approached to mimic proangiogenic microenvironment and to direct proangiogenic activities. This review highlights the types of polymers and design strategies that have been studied to promote proangiogenic activities of stem cells. In particular, scaffolds, hydrogels, and surface topographies, as well as insight into their underlying mechanisms to improve proangiogenic activities are the focuses. The strategy to promote angiogenic activities of hMSCs by controlling substrate repellency is introduced, and the future direction is proposed.