1.Peripheral Nerve Regeneration Using a Nerve Conduit with Olfactory Ensheathing Cells in a Rat Model
Jong-Yoon LEE ; Young-Ho KIM ; Boo-Young KIM ; Dae-Hyun JANG ; Sung-Wook CHOI ; So-Hyun JOEN ; Hyungyun KIM ; Sang-Uk LEE
Tissue Engineering and Regenerative Medicine 2021;18(3):453-465
BACKGROUND:
Autologous nerve grafts are the gold standard treatment for peripheral nerve injury treatment. However, this procedure cannot avoid sacrificing other nerves as a major limitation. The aim of the present study was to evaluate the potential of olfactory ensheathing cells (OECs) embedded in a nerve conduit.
METHODS:
A 10-mm segment of the sciatic nerve was resected in 21 rats, and the nerve injury was repaired with one of the following (n = 7 per group): autologous nerve graft, poly (ε-caprolactone) (PCL) conduit and OECs, and PCL conduit only. The consequent effect on nerve regeneration was measured based on the nerve conduction velocity (NCV), amplitude of the compound muscle action potential (ACMAP), wet muscle weight, histomorphometric analysis, and nerve density quantification.
RESULTS:
Histomorphometric analysis revealed nerve regeneration and angiogenesis in all groups. However, there were significant differences (p < 0.05) in the ACMAP nerve regeneration rate of the gastrocnemius and tibialis anterior muscles between the autologous graft (37.9 ± 14.3% and 39.1% ± 20.4%) and PCL only (17.8 ± 8.6% and 13.6 ± 5.8%) groups, and between the PCL only and PCL + OECs (46.3 ± 20.0% and 34.5 ± 14.6%) groups, with no differences between the autologous nerve and PCL + OEC groups (p > 0.05). No significant results in NCV, wet muscle weight, and nerve density quantification were observed among the 3 groups.
CONCLUSION
A PCL conduit with OECs enhances the regeneration of injured peripheral nerves, offering a good alternative to autologous nerve grafts.
2.Peripheral Nerve Regeneration Using a Nerve Conduit with Olfactory Ensheathing Cells in a Rat Model
Jong-Yoon LEE ; Young-Ho KIM ; Boo-Young KIM ; Dae-Hyun JANG ; Sung-Wook CHOI ; So-Hyun JOEN ; Hyungyun KIM ; Sang-Uk LEE
Tissue Engineering and Regenerative Medicine 2021;18(3):453-465
BACKGROUND:
Autologous nerve grafts are the gold standard treatment for peripheral nerve injury treatment. However, this procedure cannot avoid sacrificing other nerves as a major limitation. The aim of the present study was to evaluate the potential of olfactory ensheathing cells (OECs) embedded in a nerve conduit.
METHODS:
A 10-mm segment of the sciatic nerve was resected in 21 rats, and the nerve injury was repaired with one of the following (n = 7 per group): autologous nerve graft, poly (ε-caprolactone) (PCL) conduit and OECs, and PCL conduit only. The consequent effect on nerve regeneration was measured based on the nerve conduction velocity (NCV), amplitude of the compound muscle action potential (ACMAP), wet muscle weight, histomorphometric analysis, and nerve density quantification.
RESULTS:
Histomorphometric analysis revealed nerve regeneration and angiogenesis in all groups. However, there were significant differences (p < 0.05) in the ACMAP nerve regeneration rate of the gastrocnemius and tibialis anterior muscles between the autologous graft (37.9 ± 14.3% and 39.1% ± 20.4%) and PCL only (17.8 ± 8.6% and 13.6 ± 5.8%) groups, and between the PCL only and PCL + OECs (46.3 ± 20.0% and 34.5 ± 14.6%) groups, with no differences between the autologous nerve and PCL + OEC groups (p > 0.05). No significant results in NCV, wet muscle weight, and nerve density quantification were observed among the 3 groups.
CONCLUSION
A PCL conduit with OECs enhances the regeneration of injured peripheral nerves, offering a good alternative to autologous nerve grafts.
3.Application of an Intraoperative Neuromonitoring System Using a Surface Pressure Sensor in Parotid Surgery: A Rabbit Model Study
Eui-Suk SUNG ; Hyun-Keun KWON ; Sung-Chan SHIN ; Young-Il CHEON ; Jung-Woo LEE ; Da-Hee PARK ; Seong-Wook CHOI ; Hwa-Bin KIM ; Hye-Jin PARK ; Jin-Choon LEE ; Jung-Hoon RO ; Byung-Joo LEE
Clinical and Experimental Otorhinolaryngology 2021;14(1):131-136
Objectives:
. Facial nerve monitoring (FNM) can be used to identify the facial nerve, to obtain information regarding its course, and to evaluate its status during parotidectomy. However, there has been disagreement regarding the efficacy of FNM in reducing the incidence of facial nerve palsy during parotid surgery. Therefore, instead of using electromyography (EMG) to identify the location and state of the facial nerve, we applied an intraoperative neuromonitoring (IONM) system using a surface pressure sensor to detect facial muscle twitching. The objective of this study was to investigate the feasibility of using the IONM system with a surface pressure sensor to detect facial muscle twitching during parotidectomy.
Methods:
. We evaluated the stimulus thresholds for the detection of muscle twitching in the orbicularis oris and orbicularis oculi, as well as the amplitude and latency of EMG and the surface pressure sensor in 13 facial nerves of seven rabbits, using the same stimulus intensity.
Results:
. The surface pressure sensor detected muscle twitching in the orbicularis oris and orbicularis oculi in response to a stimulation of 0.1 mA in all 13 facial nerves. The stimulus threshold did not differ between the surface pressure sensor and EMG.
Conclusion
. The application of IONM using a surface pressure sensor during parotidectomy is noninvasive, reliable, and feasible. Therefore, the IONM system with a surface pressure sensor to measure facial muscle twitching may be an alternative to EMG for verifying the status of the facial nerve.
4.Application of Novel Intraoperative Neuromonitoring System Using an Endotracheal Tube With Pressure Sensor during Thyroid Surgery: A Porcine Model Study
Eui-Suk SUNG ; Sung-Chan SHIN ; Hyun-Keun KWON ; Jia KIM ; Da-Hee PARK ; Seong-Wook CHOI ; Sang-Hoon KIM ; Jin-Choon LEE ; Jung-Hoon RO ; Byung-Joo LEE
Clinical and Experimental Otorhinolaryngology 2020;13(3):291-298
Objectives:
. The loss of signal during intraoperative neuromonitoring (IONM) using electromyography (EMG) in thyroidectomy is one of the biggest problems. We have developed a novel IONM system with an endotracheal tube (ETT) with an attached pressure sensor instead of EMG to detect laryngeal twitching. The aim of the present study was to investigate the feasibility and reliability of this novel IONM system using an ETT with pressure sensor during thyroidectomy in a porcine model.
Methods:
. We developed an ETT-attached pressure sensor that uses the piezoelectric effect to measure laryngeal muscle twitching. Stimulus thresholds, amplitude, and latency of laryngeal twitching evaluated using the pressure sensor were compared to those measured using transcartilage needle EMG. The measured amplitude changes by EMG and the pressure sensor during recurrent laryngeal nerve (RLN) traction injury were compared.
Results:
. No significant differences in stimulus threshold intensity between EMG and the pressure sensor were observed. The EMG amplitude detected at 0.3 mA, increased with increasing stimulus intensity. When the stimulus was more than 1.0 mA, the amplitude showed a plateau. In a RLN traction injury experiment, the EMG amplitude did not recover even 20 minutes after stopping RLN traction. However, the pressure sensor showed a mostly recovery.
Conclusion
. The change in amplitude due to stimulation of the pressure sensor showed a pattern similar to EMG. Pressure sensors can be feasibly and reliably used for RLN traction injury prediction, RLN identification, and preservation through the detection of laryngeal muscle twitching. Our novel IONM system that uses an ETT with an attached pressure sensor to measure the change of surface pressure can be an alternative to EMG in the future.
5.In Vivo Safety and Regeneration of Long-Term Transported Amniotic Fluid Stem Cells for Renal Regeneration
Na hee YU ; So Young CHUN ; Yun Sok HA ; Hyun Tae KIM ; Eugene LIH ; Dae Hwan KIM ; Jeongshik KIM ; Jae Wook CHUNG ; Phil Hyun SONG ; Eun Sang YOO ; Sung Kwang CHUNG ; Dong Keun HAN ; Bum Soo KIM ; Tae Gyun KWON
Tissue Engineering and Regenerative Medicine 2019;16(1):81-92
BACKGROUND: Despite major progress in stem cell therapy, our knowledge of the characteristics and tissue regeneration potency of long-term transported cells is insufficient. In a previous in vitro study, we established the optimal cell transport conditions for amniotic fluid stem cells (AFSCs). In the present study, the target tissue regeneration of long-term transported cells was validated in vivo. METHODS: For renal regeneration, transported AFSCs were seeded on a poly(lactide-co-glycolide) scaffold and implanted in a partially resected kidney. The target tissue regeneration of the transported cells was compared with that of freshly harvested cells in terms of morphological reconstruction, histological microstructure reformation, immune cell infiltration, presence of induced cells, migration into remote organs, expression of inflammation/fibrosis/renal differentiation-related factors, and functional recovery. RESULTS: The kidney implanted with transported cells showed recovery of total kidney volume, regeneration of glomerular/renal tubules, low CD4/CD8 infiltration, and no occurrence of cancer during 40 weeks of observation. The AFSCs gradually disappeared and did not migrate into the liver, lung, or spleen. We observed low expression levels of proinflammatory cytokines and fibrotic factors; enhanced expression of the genes Wnt4, Pax2, Wt1, and Emx2; and significantly reduced blood urea nitrogen and creatinine values. There were no statistical differences between the performance of freshly harvested cells and that of the transported cells. CONCLUSION: This study demonstrates that long-term transported cells under optimized conditions can be used for cell therapy without adverse effects on stem cell characteristics, in vivo safety, and tissue regeneration potency.
Amniotic Fluid
;
Blood Urea Nitrogen
;
Cell- and Tissue-Based Therapy
;
Creatinine
;
Cytokines
;
Female
;
In Vitro Techniques
;
Kidney
;
Liver
;
Lung
;
Polyglactin 910
;
Regeneration
;
Spleen
;
Stem Cells
6.Three-Dimensional Spheroid Formation of Cryopreserved Human Dental Follicle-Derived Stem Cells Enhances Pluripotency and Osteogenic Induction Properties
Hyo Jung KIM ; Iel Yong SUNG ; Yeong Cheol CHO ; Min Su KANG ; Gyu Jin RHO ; June Ho BYUN ; Won Uk PARK ; Myeong Gyun SON ; Bong Wook PARK ; Hyeon Jeong LEE ; Young Hoon KANG
Tissue Engineering and Regenerative Medicine 2019;16(5):513-523
BACKGROUND: Enhancement and maintenance of the stemness of mesenchymal stem cells (MSCs) is one of the most important factors contributing to the successful in vivo therapeutic application of these cells. In this regard, three-dimensional (3D) spheroid formation has been developed as reliable method for increasing the pluripotency of MSCs. Moreover, using a new protocol, we have previously shown that dental tissues of extracted wisdom teeth can be effectively cryopreserved for subsequent use as a source of autologous stem cells. The main purpose of this study is to analyze the stemness and in vitro osteogenic differentiation potential of 3D spheroid dental MSCs compared with conventional monolayer cultured MSCs. METHODS: In this study, MSC-characterized stem cells were isolated and cultured from long-term cryopreserved dental follicles (hDFSCs), and then 2D hDFSCs were cultured under 3D spheroid-forming conditions using a newly designed microchip dish. The spheroids (3D hDFSCs) thus produced were investigated and characterized with respect to stemness, MSC marker expression, apoptosis, cell cycle analysis, extracellular matrix (ECM) production, and osteogenic and adipogenic differentiation properties. RESULTS: In terms of MSC and senescence markers, spheroid cells showed no difference when compared with 2D hDFSCs; however, 3D hDFSCs were observed to have a higher proportion of cell cycle arrest and a larger number of apoptotic cells. Moreover, spheroids showed substantially increased levels of pluripotency marker (early transcription factors) and ECM protein expression. Compared with 2D hDFSCs, there was also a notable enhancement in the osteogenic induction potential of spheroids, although no differences were observed with respect to in vitro adipogenesis. CONCLUSION: To the best of our knowledge, this is the first study to demonstrate the application of a spheroid culture system for dental follicle-derived stem cells using a microchip dish. Although further studies are needed, including in vivo transplantation, the results obtained in this study indicate that spheroid hDFSCs derived from cryopreserved dental follicle tissues could be used as a valuable source of autologous stem cells for bone tissue regeneration.
Adipogenesis
;
Aging
;
Apoptosis
;
Bone and Bones
;
Cell Cycle
;
Cell Cycle Checkpoints
;
Dental Sac
;
Extracellular Matrix
;
Humans
;
In Vitro Techniques
;
Mesenchymal Stromal Cells
;
Methods
;
Molar, Third
;
Osteogenesis
;
Regeneration
;
Stem Cells
7.Development of a Novel Intraoperative Neuromonitoring System Using an Accelerometer Sensor in Thyroid Surgery: A Porcine Model Study
Eui Suk SUNG ; Jin Choon LEE ; Sung Chan SHIN ; Hyun Keun KWON ; Han Seul NA ; Da Hee PARK ; Seong Wook CHOI ; Jung Hoon RO ; Byung Joo LEE
Clinical and Experimental Otorhinolaryngology 2019;12(4):420-426
OBJECTIVES: The sensitivity and positive predictive value of widely used intraoperative neuromonitoring (IONM) using electromyography (EMG) of the vocalis muscle in thyroid surgery are controversial. Thus, we developed a novel IONM system with an accelerometer sensor that uses the piezoelectric effect instead of EMG to detect laryngeal twitching. The objective of this study was to evaluate the feasibility and safety of this novel IONM system during thyroid surgery in a porcine model. METHODS: We developed an accelerometer sensor that uses the piezoelectric effect to measure laryngeal twitching in three dimensions. This novel accelerometer sensor was placed in the anterior neck skin (transcutaneous) or postcricoid area. Stimulus thresholds, amplitude, and latency of laryngeal twitching measured using the accelerometer sensor were compared to those measured through EMG of the vocalis muscle. RESULTS: The amplitudes of the accelerometer sensor at the anterior neck and postcricoid area were significantly lower than those of EMG because of differences in the measurement method used to evaluate laryngeal movement. However, no significant differences in stimulus thresholds between the EMG endotracheal tube and transcutaneous or postcricoid accelerometer sensors were observed. CONCLUSION: Accelerometer sensors located at the anterior neck or postcricoid area were able to identify laryngeal twitching. The stimulus intensity measured with these sensors was equivalent to that from conventional vocalis EMG. Our novel IONM system with an accelerometer sensor that checks changes in surface acceleration can be an alternative to EMG of the vocalis muscle for IONM in the future.
Acceleration
;
Electromyography
;
Laryngeal Muscles
;
Methods
;
Neck
;
Recurrent Laryngeal Nerve
;
Skin
;
Thyroid Gland
;
Thyroidectomy
8.Reverse Warburg Effect-Related Mitochondrial Activity and ¹⁸F-FDG Uptake in Invasive Ductal Carcinoma
Byung Wook CHOI ; Young Ju JEONG ; Sung Hwan PARK ; Hoon Kyu OH ; Sungmin KANG
Nuclear Medicine and Molecular Imaging 2019;53(6):396-405
PURPOSE: We evaluated the relationship between fluorine-18 fluoro-2-deoxy-glucose (¹⁸F-FDG) uptake and mitochondrial activity in cancer cells and investigated the prognostic implications of this relationship in patients with invasive ductal carcinoma of the breast (IDCB).METHODS: One hundred forty-six patients with primary IDCB who underwent preoperative ¹⁸F-FDG PET/CT followed by curative surgical resection were enrolled in the current study. Mitochondrial activity of cancer cells was assessed based on translocase of outer mitochondrial membrane 20 (TOMM20) expression and cytochrome C oxidase (COX) activity. A Pearson's correlation analysis was used to assess the relationship between the maximum standardized uptake value of the primary tumour (pSUVmax) and mitochondrial activity. Clinicopathological factors, including pSUVmax, histological grade, oestrogen receptor (ER), progesterone receptor (PR), and TOMM20 expression; and COX activity, were assessed for the prediction of disease-free survival (DFS) using the Kaplan–Meier method and Cox proportional hazards model.RESULTS: Fourteen of the 146 subjects (9.6%) showed tumour recurrence. There was a significant positive correlation between ¹⁸F-FDG uptake and the mitochondrial activity of cancer cells in patients with IDCB, and increased ¹⁸F-FDG uptake and mitochondrial activity were significantly associated with a shorter DFS. Additionally, results from the receiver-operating curve analysis demonstrated that the cut-off values of pSUVmax, TOMM20 expression, and COX activity for the prediction of DFS were 7.76, 4, and 5, respectively. Further, results from the univariate analysis revealed that pSUVmax, TOMM20 expression, PR status, and histologic grade were significantly associated with DFS; however, the multivariate analysis revealed that only pSUVmax was associated with DFS (HR, 6.51; 95% CI, 1.91, 22.20; P = 0.003).CONCLUSIONS: The assessment of preoperative ¹⁸F-FDG uptake and post-surgical mitochondrial activity may be used for the prediction of DFS in patients with IDCB.
Breast
;
Breast Neoplasms
;
Carcinoma, Ductal
;
Disease-Free Survival
;
Electron Transport Complex IV
;
Humans
;
Methods
;
Mitochondrial Membranes
;
Multivariate Analysis
;
Positron-Emission Tomography and Computed Tomography
;
Proportional Hazards Models
;
Receptors, Progesterone
;
Recurrence
9.Reverse Warburg Effect-Related Mitochondrial Activity and ¹â¸F-FDG Uptake in Invasive Ductal Carcinoma
Byung Wook CHOI ; Young Ju JEONG ; Sung Hwan PARK ; Hoon Kyu OH ; Sungmin KANG
Nuclear Medicine and Molecular Imaging 2019;53(6):396-405
PURPOSE:
We evaluated the relationship between fluorine-18 fluoro-2-deoxy-glucose (¹â¸F-FDG) uptake and mitochondrial activity in cancer cells and investigated the prognostic implications of this relationship in patients with invasive ductal carcinoma of the breast (IDCB).
METHODS:
One hundred forty-six patients with primary IDCB who underwent preoperative ¹â¸F-FDG PET/CT followed by curative surgical resection were enrolled in the current study. Mitochondrial activity of cancer cells was assessed based on translocase of outer mitochondrial membrane 20 (TOMM20) expression and cytochrome C oxidase (COX) activity. A Pearson's correlation analysis was used to assess the relationship between the maximum standardized uptake value of the primary tumour (pSUVmax) and mitochondrial activity. Clinicopathological factors, including pSUVmax, histological grade, oestrogen receptor (ER), progesterone receptor (PR), and TOMM20 expression; and COX activity, were assessed for the prediction of disease-free survival (DFS) using the Kaplan–Meier method and Cox proportional hazards model.
RESULTS:
Fourteen of the 146 subjects (9.6%) showed tumour recurrence. There was a significant positive correlation between ¹â¸F-FDG uptake and the mitochondrial activity of cancer cells in patients with IDCB, and increased ¹â¸F-FDG uptake and mitochondrial activity were significantly associated with a shorter DFS. Additionally, results from the receiver-operating curve analysis demonstrated that the cut-off values of pSUVmax, TOMM20 expression, and COX activity for the prediction of DFS were 7.76, 4, and 5, respectively. Further, results from the univariate analysis revealed that pSUVmax, TOMM20 expression, PR status, and histologic grade were significantly associated with DFS; however, the multivariate analysis revealed that only pSUVmax was associated with DFS (HR, 6.51; 95% CI, 1.91, 22.20; P = 0.003).
CONCLUSIONS
The assessment of preoperative ¹â¸F-FDG uptake and post-surgical mitochondrial activity may be used for the prediction of DFS in patients with IDCB.
10.Laminin and Platelet-Derived Growth Factor-BB Promote Neuronal Differentiation of Human Urine-Derived Stem Cells.
Jung Yeon KIM ; So Young CHUN ; Jin Sung PARK ; Jae Wook CHUNG ; Yun Sok HA ; Jun Nyung LEE ; Tae Gyun KWON
Tissue Engineering and Regenerative Medicine 2018;15(2):195-209
Urine-derived stem cells (USCs) are considered as a promising cell source capable of neuronal differentiation. In addition, specific growth factors and extracellular matrix are essential for enhancing their neuronal differentiation efficiency. In this study, we investigated the possibility of neuronal differentiation of USCs and the role of laminin and platelet-derived growth factor BB (PDGF-BB) as promoting factors. USCs were isolated from fresh urine of healthy donors. Cultured USCs were adherent to the plate and their morphology was similar to the cobblestone. In addition, they showed chromosome stability, rapid proliferation rate, colony forming capacity, and mesenchymal stem cell characteristics. For inducing the neuronal differentiation, USCs were cultured for 14 days in neuronal differentiation media supplemented with/without laminin and/or PDGF-BB. To identify the expression of neuronal markers, RT-PCR, flow cytometry analysis and immunocytochemistry were used. After neuronal induction, the cells showed neuron-like morphological change and high expression level of neuronal markers. In addition, laminin and PDGF-BB respectively promoted the neuronal differentiation of USCs and the combination of laminin and PDGF-BB showed a synergistic effect for the neuronal differentiation of USCs. In conclusion, USCs are noteworthy cell source in the field of neuronal regeneration and laminin and PDGF-BB promote their neuronal differentiation efficiency.
Chromosomal Instability
;
Extracellular Matrix
;
Flow Cytometry
;
Humans*
;
Immunohistochemistry
;
Intercellular Signaling Peptides and Proteins
;
Laminin*
;
Mesenchymal Stromal Cells
;
Neurons*
;
Platelet-Derived Growth Factor
;
Regeneration
;
Stem Cells*
;
Tissue Donors

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