32 results on '"Young-Joon Seol"'
Search Results
2. Multi-tissue interactions in an integrated three-tissue organ-on-a-chip platform
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Aleksander Skardal, Sean V. Murphy, Mahesh Devarasetty, Ivy Mead, Hyun-Wook Kang, Young-Joon Seol, Yu Shrike Zhang, Su-Ryon Shin, Liang Zhao, Julio Aleman, Adam R. Hall, Thomas D. Shupe, Andre Kleensang, Mehmet R. Dokmeci, Sang Jin Lee, John D. Jackson, James J. Yoo, Thomas Hartung, Ali Khademhosseini, Shay Soker, Colin E. Bishop, and Anthony Atala
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Medicine ,Science - Abstract
Abstract Many drugs have progressed through preclinical and clinical trials and have been available – for years in some cases – before being recalled by the FDA for unanticipated toxicity in humans. One reason for such poor translation from drug candidate to successful use is a lack of model systems that accurately recapitulate normal tissue function of human organs and their response to drug compounds. Moreover, tissues in the body do not exist in isolation, but reside in a highly integrated and dynamically interactive environment, in which actions in one tissue can affect other downstream tissues. Few engineered model systems, including the growing variety of organoid and organ-on-a-chip platforms, have so far reflected the interactive nature of the human body. To address this challenge, we have developed an assortment of bioengineered tissue organoids and tissue constructs that are integrated in a closed circulatory perfusion system, facilitating inter-organ responses. We describe a three-tissue organ-on-a-chip system, comprised of liver, heart, and lung, and highlight examples of inter-organ responses to drug administration. We observe drug responses that depend on inter-tissue interaction, illustrating the value of multiple tissue integration for in vitro study of both the efficacy of and side effects associated with candidate drugs.
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- 2017
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3. Neural cell integration into 3D bioprinted skeletal muscle constructs accelerates restoration of muscle function
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In Kap Ko, Ji Hyun Kim, Young-Joon Seol, Sang Jin Lee, Ickhee Kim, Anthony Atala, and James J. Yoo
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Male ,Time Factors ,General Physics and Astronomy ,02 engineering and technology ,Regenerative medicine ,Biomimetic Materials ,Myocyte ,lcsh:Science ,Neural cell ,Neurons ,0303 health sciences ,Multidisciplinary ,Cell Differentiation ,Hydrogels ,021001 nanoscience & nanotechnology ,Neural stem cell ,Cell biology ,medicine.anatomical_structure ,Printing, Three-Dimensional ,0210 nano-technology ,Muscle tissue ,Cell Survival ,Science ,Myoblasts, Skeletal ,Neuromuscular Junction ,Biology ,General Biochemistry, Genetics and Molecular Biology ,Neuromuscular junction ,Article ,03 medical and health sciences ,Muscular Diseases ,medicine ,Animals ,Humans ,Tissue engineering ,Muscle, Skeletal ,030304 developmental biology ,Cell Proliferation ,Guided Tissue Regeneration ,Bioprinting ,Skeletal muscle ,General Chemistry ,Rats ,Disease Models, Animal ,Feasibility Studies ,lcsh:Q ,Nerve Net ,Muscle architecture - Abstract
A bioengineered skeletal muscle construct that mimics structural and functional characteristics of native skeletal muscle is a promising therapeutic option to treat extensive muscle defect injuries. We previously showed that bioprinted human skeletal muscle constructs were able to form multi-layered bundles with aligned myofibers. In this study, we investigate the effects of neural cell integration into the bioprinted skeletal muscle construct to accelerate functional muscle regeneration in vivo. Neural input into this bioprinted skeletal muscle construct shows the improvement of myofiber formation, long-term survival, and neuromuscular junction formation in vitro. More importantly, the bioprinted constructs with neural cell integration facilitate rapid innervation and mature into organized muscle tissue that restores normal muscle weight and function in a rodent model of muscle defect injury. These results suggest that the 3D bioprinted human neural-skeletal muscle constructs can be rapidly integrated with the host neural network, resulting in accelerated muscle function restoration., 3D bioprinting of skeletal muscle using primary human muscle progenitor cells results in correct muscle architecture, but functional restoration in rodent models is limited. Here the authors include human neural stem cells into bioprinted skeletal muscle and observe improved architecture and function in vivo.
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- 2020
4. 3D Bioprinted Human Skeletal Muscle Constructs for Muscle Function Restoration
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Hyun Wook Kang, Anthony Atala, Ji Hyun Kim, Young Koo Lee, James J. Yoo, In Kap Ko, Sang Jin Lee, Young-Joon Seol, and School of Biomedical Engineering and Sciences
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0301 basic medicine ,loss injury ,lcsh:Medicine ,02 engineering and technology ,in-vitro ,Biology ,engineered muscle ,Article ,law.invention ,03 medical and health sciences ,Tissue engineering ,law ,medicine ,Humans ,Progenitor cell ,Muscle, Skeletal ,lcsh:Science ,Cells, Cultured ,3D bioprinting ,Multidisciplinary ,Tissue Engineering ,Tissue Scaffolds ,Myogenesis ,rat model ,Regeneration (biology) ,lcsh:R ,Bioprinting ,Skeletal muscle ,tissue ,cell ,021001 nanoscience & nanotechnology ,Muscle bundle ,030104 developmental biology ,medicine.anatomical_structure ,myotubes ,regeneration ,Printing, Three-Dimensional ,lcsh:Q ,hydrogel ,vivo ,0210 nano-technology ,Function (biology) ,Biomedical engineering - Abstract
A bioengineered skeletal muscle tissue as an alternative for autologous tissue flaps, which mimics the structural and functional characteristics of the native tissue, is needed for reconstructive surgery. Rapid progress in the cell-based tissue engineering principle has enabled in vitro creation of cellularized muscle-like constructs; however, the current fabrication methods are still limited to build a three-dimensional (3D) muscle construct with a highly viable, organized cellular structure with the potential for a future human trial. Here, we applied 3D bioprinting strategy to fabricate an implantable, bioengineered skeletal muscle tissue composed of human primary muscle progenitor cells (hMPCs). The bioprinted skeletal muscle tissue showed a highly organized multi-layered muscle bundle made by viable, densely packed, and aligned myofiber-like structures. Our in vivo study presented that the bioprinted muscle constructs reached 82% of functional recovery in a rodent model of tibialis anterior (TA) muscle defect at 8 weeks of post-implantation. In addition, histological and immunohistological examinations indicated that the bioprinted muscle constructs were well integrated with host vascular and neural networks. We demonstrated the potential of the use of the 3D bioprinted skeletal muscle with a spatially organized structure that can reconstruct the extensive muscle defects. Wake Forest Clinical and Translational Science Institute [UL1 TR001420]; Army; Navy; NIH; Air Force; VA; Health Affairs [W81XWH-14-2-0004]; U.S. Army Medical Research Acquisition Activity, Fort Detrick MD [21702-5014]; Basic Science Research Program through the National Research Foundation of Korea (NRF) - Ministry of Education, Science, and Technology [2012R1A6A3A03040684] We thank H. S. Kim, J. S. Lee, and T. Bledsoe for a surgical procedure, Regenerative Medicine Clinical Center (RMCC) for hMPCs isolation, M. Devarasetty for imaging, and Y. M. Ju for technical assistance. The authors thank K. Klein at the Wake Forest Clinical and Translational Science Institute (UL1 TR001420) for editorial assistance. This work was supported by the Army, Navy, NIH, Air Force, VA and Health Affairs to support the AFIRM II effort under Award No. W81XWH-14-2-0004. The U.S. Army Medical Research Acquisition Activity, 820 Chandler Street, Fort Detrick MD 21702-5014 is the awarding and administering acquisition office. Opinions, interpretations, conclusions, and recommendations are those of the author and are not necessarily endorsed by the Department of Defense. J.H.K. was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science, and Technology (2012R1A6A3A03040684).
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- 2018
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5. Development and analysis of three-dimensional (3D) printed biomimetic ceramic
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Jung-Seob Lee, Min Sung, Wonkyu Moon, Young-Joon Seol, Jeong-Hoon Oh, Dong-Woo Cho, and Sung Won Kim
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Materials science ,Incus ,3D printing ,02 engineering and technology ,Industrial and Manufacturing Engineering ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Ceramic ,Electrical and Electronic Engineering ,Composite material ,030223 otorhinolaryngology ,Stapes ,Ossicles ,business.industry ,Mechanical Engineering ,Malleus ,021001 nanoscience & nanotechnology ,Finite element method ,Vibration ,medicine.anatomical_structure ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology ,business ,Biomedical engineering - Abstract
Many finite element (FE) models have been designed based on geometric information from computed tomography (CT) data, and validated via comparison with experimental results for human cadaver ossicular bones. Here, we describe a novel method for developing and analyzing the biomimetic ceramic ossicles (BCO) in combination with 3D printing technology, and we establish an FE model of the BCO for analyzing vibration performance. Novel biomimetic ceramic ossicles (BCO) made of hydroxyapatite (HA) were fabricated using 3D printing technology, and their vibration properties were measured. We created a 3D model of the BCO using computer-aided design, which corresponds to the ossicular structure and geometry, and created an FE model of the human ossicles via a comparison of experimental and simulated vibrations to investigate the characteristics of the ossicular chain. The FE model was established based on the displacements of the malleus, incus, and stapes, which was analyzed using an externally applied vibrational force.
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- 2016
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6. MP38-04 BIOPRINTED OVARY-ON-A-CHIP PLATFORM AS A MODEL OF OVARIAN PHYSIOLOGY AND DISEASE
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Young-Joon Seol, Anthony Atala, James Jackson, Myung Jae Jeon, Young Sik Choi, Il Dong Kim, and James J. Yoo
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Ovarian physiology ,Cell type ,medicine.anatomical_structure ,business.industry ,Urology ,Microfluidic channel ,medicine ,Ovary ,business ,Cell biology - Abstract
INTRODUCTION AND OBJECTIVE:Organ-on-a-chip is a microengineered biomimetic system containing microfluidic channels and tissue-specific cell types, which replicate functional units of living organs ...
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- 2020
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7. 3D Bioprinted BioMask for Facial Skin Reconstruction
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Hyungseok Lee, Anthony Atala, Joshua S. Copus, James J. Yoo, Young-Joon Seol, Sang Jin Lee, Hyun Wook Kang, and Dong-Woo Cho
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0301 basic medicine ,Skin wound ,integumentary system ,business.industry ,Biomedical Engineering ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Article ,Computer Science Applications ,Facial skin ,03 medical and health sciences ,Wound care ,030104 developmental biology ,medicine.anatomical_structure ,Tissue engineering ,Dermis ,Self-healing hydrogels ,medicine ,Effective treatment ,0210 nano-technology ,business ,Biotechnology ,Biomedical engineering ,Histological examination - Abstract
Skin injury to the face remains one of the greatest challenges in wound care due to the varied contours and complex movement of the face. Current treatment strategies for extensive facial burns are limited to the use of autografts, allografts, and skin substitutes, and these often result in scarring, infection, and graft failure. Development of an effective treatment modality will greatly improve the quality of life and social integration of the affected individuals. In this proof of concept study, we developed a novel strategy, called "BioMask", which is a customized bioengineered skin substitute combined with a wound dressing layer that snugly fits onto the facial wounds. To achieve this goal, three-dimensional (3D) bioprinting principle was used to fabricate the BioMask that could be customized by patients' clinical images such as computed tomography (CT) data. Based on a face CT image, a wound dressing material and cell-laden hydrogels were precisely dispensed and placed in a layer-by-layer fashion by the control of air pressure and 3-axis stage. The resulted miniature BioMask consisted of three layers; a porous polyurethane (PU) layer, a keratinocyte-laden hydrogel layer, and a fibroblast-laden hydrogel layer. To validate this novel concept, the bioprinted BioMask was applied to a skin wound on a pre-fabricated face-shaped structure in mice. Through this in vivo study using the 3D BioMask, skin contraction and histological examination showed the regeneration of skin tissue, consisting of epidermis and dermis layers, on the complex facial wounds. Consequently, effective and rapid restoration of aesthetic and functional facial skin would be a significant improvement to the current issues a facial wound patient experience.
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- 2018
8. Scientific Reports
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Su Ryon Shin, Julio Aleman, Thomas Shupe, Ivy Mead, Shay Soker, Anthony Atala, Aleksander Skardal, Andre Kleensang, Ali Khademhosseini, John D. Jackson, Liang Zhao, Mahesh Devarasetty, Yu Shrike Zhang, James J. Yoo, Hyun Wook Kang, Sang Jin Lee, Adam R. Hall, Colin E. Bishop, Sean V. Murphy, Mehmet R. Dokmeci, Thomas Hartung, Young-Joon Seol, and School of Biomedical Engineering and Sciences
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0301 basic medicine ,disease-models ,Microfluidics ,Normal tissue ,Tissue integration ,02 engineering and technology ,chemotherapy ,Bioinformatics ,Lab-On-A-Chip Devices ,Drug Discovery ,Medicine ,2.1 Biological and endogenous factors ,Aetiology ,Lung ,media_common ,Multidisciplinary ,bleomycin ,Liver Disease ,Heart ,Equipment Design ,021001 nanoscience & nanotechnology ,3. Good health ,Organoids ,Liver ,5.1 Pharmaceuticals ,Development of treatments and therapeutic interventions ,0210 nano-technology ,Drug ,tumor ,Science ,media_common.quotation_subject ,cardiotoxicity ,spheroids ,Organ-on-a-chip ,Article ,03 medical and health sciences ,ddc:570 ,In vitro study ,Humans ,hydrogels ,business.industry ,Drug candidate ,Drug administration ,030104 developmental biology ,Good Health and Well Being ,Tissue Array Analysis ,drug screening applications ,business ,Digestive Diseases ,Neuroscience ,discovery ,Function (biology) - Abstract
Many drugs have progressed through preclinical and clinical trials and have been available - for years in some cases -before being recalled by the FDA for unanticipated toxicity in humans. One reason for such poor translation from drug candidate to successful use is a lack of model systems that accurately recapitulate normal tissue function of human organs and their response to drug compounds. Moreover, tissues in the body do not exist in isolation, but reside in a highly integrated and dynamically interactive environment, in which actions in one tissue can affect other downstream tissues. Few engineered model systems, including the growing variety of organoid and organ-on-a-chip platforms, have so far reflected the interactive nature of the human body. To address this challenge, we have developed an assortment of bioengineered tissue organoids and tissue constructs that are integrated in a closed circulatory perfusion system, facilitating inter-organ responses. We describe a three-tissue organ-on-a-chip system, comprised of liver, heart, and lung, and highlight examples of inter-organ responses to drug administration. We observe drug responses that depend on inter-tissue interaction, illustrating the value of multiple tissue integration for in vitro study of both the efficacy of and side effects associated with candidate drugs. Defense Threat Reduction Agency (DTRA) under Space and Naval Warfare Systems Center Pacific (SSC PACIFIC) [N6601-13-C-2027]; Comprehensive Cancer Center of Wake Forest University NCI CCSG [P30CA012197] The authors gratefully thank Dr. Pedro Baptista for aid in the drug metabolism studies, Steven Forsythe and Meiei Wan for technical aid in maintaining liver and cardiac organoid viability, and Dipasri Konar and Katherine Crowell for technical aid in the lung-on-a-chip operation. The authors gratefully acknowledge funding by the Defense Threat Reduction Agency (DTRA) under Space and Naval Warfare Systems Center Pacific (SSC PACIFIC) Contract No. N6601-13-C-2027. The publication of this material does not constitute approval by the government of the findings or conclusions herein. Proteomics and Metabolomics Core Lab services are supported by the Comprehensive Cancer Center of Wake Forest University NCI CCSG P30CA012197 grant.
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- 2017
9. Bioprinting technology and its applications
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Anthony Atala, James J. Yoo, Young-Joon Seol, Hyun Wook Kang, and Sang Jin Lee
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Pulmonary and Respiratory Medicine ,Tissue Engineering ,Myocardial tissue ,business.industry ,Bioprinting ,Nanotechnology ,General Medicine ,Regenerative Medicine ,Tissue engineering ,Humans ,Medicine ,Surgery ,Cardiology and Cardiovascular Medicine ,business ,Cells, Cultured - Abstract
Summary Bioprinting technology has emerged as a powerful tool for building tissue and organ structures in the field of tissue engineering. This technology allows precise placement of cells, biomaterials and biomolecules in spatially predefined locations within confined three-dimensional (3D) structures. Various bioprinting technologies have been developed and utilized for applications in life sciences, ranging from studying cellular mechanisms to constructing tissues and organs for implantation, including heart valve, myocardial tissue, trachea and blood vessels. In this article, we introduce the general principles and limitations of the most widely used bioprinting technologies, including jetting- and extrusion-based systems. Application-based research focused on tissue regeneration is presented, as well as the current challenges that hamper clinical utility of bioprinting technology.
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- 2014
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10. Development of hybrid scaffolds using ceramic and hydrogel for articular cartilage tissue regeneration
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Young-Joon Seol, Dong-Woo Cho, Won-Ju Jeong, Shin-Yoon Kim, Tae-Ho Kim, and Ju Young Park
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Scaffold ,Materials science ,Hyaline cartilage ,Cartilage ,Regeneration (biology) ,technology, industry, and agriculture ,Metals and Alloys ,Biomedical Engineering ,Articular cartilage ,Bone tissue ,complex mixtures ,Hydrogel scaffold ,Biomaterials ,medicine.anatomical_structure ,Tissue engineering ,Ceramics and Composites ,medicine ,Biomedical engineering - Abstract
The regeneration of articular cartilage consisting of hyaline cartilage and hydrogel scaffolds has been generally used in tissue engineering. However, success in in vivo studies has been rarely reported. The hydrogel scaffolds implanted into articular cartilage defects are mechanically unstable and it is difficult for them to integrate with the surrounding native cartilage tissue. Therefore, it is needed to regenerate cartilage and bone tissue simultaneously. We developed hybrid scaffolds with hydrogel scaffolds for cartilage tissue and with ceramic scaffolds for bone tissue. For in vivo study, hybrid scaffolds were press-fitted into osteochondral tissue defects in a rabbit knee joints and the cartilage tissue regeneration in blank, hydrogel scaffolds, and hybrid scaffolds was compared. In 12th week after implantation, the histological and immunohistochemical analyses were conducted to evaluate the cartilage tissue regeneration. In the blank and hydrogel scaffold groups, the defects were filled with fibrous tissues and the implanted hydrogel scaffolds could not maintain their initial position; in the hybrid scaffold group, newly generated cartilage tissues were morphologically similar to native cartilage tissues and were smoothly connected to the surrounding native tissues. This study demonstrates hybrid scaffolds containing hydrogel and ceramic scaffolds can provide mechanical stability to hydrogel scaffolds and enhance cartilage tissue regeneration at the defect site.
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- 2014
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11. Combined Effect of Three Types of Biophysical Stimuli for Bone Regeneration
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Woon-Jae Yong, Kyung Shin Kang, Jung Min Hong, Dong-Woo Cho, Jong-Won Rhie, Young-Joon Seol, and Young Hun Jeong
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Calcium Phosphates ,Male ,Bone Regeneration ,Cell Survival ,Polyesters ,Cellular differentiation ,Biomedical Engineering ,Core Binding Factor Alpha 1 Subunit ,Bioengineering ,Stimulation ,Biology ,Bone tissue ,Biochemistry ,Biophysical Phenomena ,Biomaterials ,Bioreactors ,Polylactic Acid-Polyglycolic Acid Copolymer ,Osteogenesis ,Stress, Physiological ,In vivo ,medicine ,Animals ,Humans ,Lactic Acid ,Bone regeneration ,Mice, Inbred BALB C ,Regeneration (biology) ,Cell Differentiation ,Original Articles ,Immunohistochemistry ,Lamins ,Cell biology ,medicine.anatomical_structure ,Gene Expression Regulation ,Stem cell ,Polyglycolic Acid ,Biomedical engineering - Abstract
Pretreatment using various types of biophysical stimuli could provide appropriate potential to cells during construction of the engineered tissue in vitro. We hypothesized that multiple combinations of these biophysical stimuli could enhance osteogenic differentiation in vitro and bone formation in vivo. Cyclic strain, an electromagnetic field, and ultrasound were selected and combined as effective stimuli for osteogenic differentiation using a developed bioreactor. Here we report the experimental evaluation of the osteogenic effects of various combinations of three different biophysical stimuli in vitro and in vivo using human adipose-derived stem cells (ASCs). Osteogenic differentiation of ASCs was accelerated by multiple-combination biophysical stimulation in vitro. However, both single stimulation and double-combination stimulation were sufficient to accelerate bone regeneration in vivo, while the osteogenic marker expression of those groups was not as high as that of triple-combination stimulation in vitro. We inferred from these data that ASCs appropriately differentiated into the osteogenic lineage by biophysical stimulation could be a better option for accelerating bone formation in vivo than relatively undifferentiated or completely differentiated ASCs. Although many questions remain about the mechanisms of combined effects of various biophysical stimuli, this approach could be a more powerful tool for bone tissue regeneration.
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- 2014
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12. Improving mechanical properties of alginate hydrogel by reinforcement with ethanol treated polycaprolactone nanofibers
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Young Hun Jeong, Jongwan Lee, Dong-Woo Cho, Young-Joon Seol, and Jinah Jang
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Materials science ,Biocompatibility ,Mechanical Engineering ,Industrial and Manufacturing Engineering ,Electrospinning ,chemistry.chemical_compound ,Compressive strength ,chemistry ,Mechanics of Materials ,Nanofiber ,Polycaprolactone ,Self-healing hydrogels ,Volume fraction ,Ceramics and Composites ,Surface modification ,Composite material - Abstract
Hydrogels offer interesting possibilities in various biomedical applications, including tissue regeneration, drug delivery, and cell therapy, due to excellent biocompatibility and good nutrient and oxygen transportation abilities. However, most of these applications require improvements in mechanical properties and functionalization. In this study, a novel technique for fabricating 3D nanofiber-reinforced hydrogel composites is described as a means of enhancing the strength and durability of hydrogels. The method is based on the layer-by-layer electrospinning of nanofibers on an evenly spread, thin hydrogel solution. A coaxial nozzle was introduced for electrospinning highly wettable ethanol-treated nanofibers. This process enhanced the compatibility between the nanofiber reinforcements and the hydrogel matrix. The compressive strength and stiffness of the resulting nanofiber-reinforced hydrogel composites were enhanced to ∼221% and ∼434% compared to the pure hydrogel, respectively. Moreover, the equilibrium modulus was increased by a factor of nearly 1.73 when the volume fraction of nanofibers was 0.085. It was demonstrated that a 3D nanofiber-reinforced hydrogel composite could be fabricated without the cumbersome stacking of hydrogel-coated fiber meshes. Furthermore, the mechanical properties of the reinforced composites can be modulated by adjusting the volume fraction of nanofibers.
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- 2013
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13. Bioprinting Cellularized Constructs Using a Tissue-specific Hydrogel Bioink
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Anthony Atala, Aleksander Skardal, Colin E. Bishop, Hyun Wook Kang, Thomas Shupe, Young-Joon Seol, Steven Forsythe, Shay Soker, and Mahesh Devarasetty
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0301 basic medicine ,food.ingredient ,Cell Survival ,General Chemical Engineering ,Bioengineering ,02 engineering and technology ,Gelatin ,General Biochemistry, Genetics and Molecular Biology ,Hydrogel, Polyethylene Glycol Dimethacrylate ,Polyethylene Glycols ,Extracellular matrix ,03 medical and health sciences ,food ,Tissue specific ,Humans ,Viability assay ,Tissue construct ,Hyaluronic Acid ,General Immunology and Microbiology ,Tissue Engineering ,Tissue Scaffolds ,Chemistry ,General Neuroscience ,Bioprinting ,High cell ,Hydrogels ,021001 nanoscience & nanotechnology ,Extracellular Matrix ,030104 developmental biology ,Self-healing hydrogels ,0210 nano-technology ,Biofabrication ,Biomedical engineering - Abstract
Bioprinting has emerged as a versatile biofabrication approach for creating tissue engineered organ constructs. These constructs have potential use as organ replacements for implantation in patients, and also, when created on a smaller size scale as model "organoids" that can be used in in vitro systems for drug and toxicology screening. Despite development of a wide variety of bioprinting devices, application of bioprinting technology can be limited by the availability of materials that both expedite bioprinting procedures and support cell viability and function by providing tissue-specific cues. Here we describe a versatile hyaluronic acid (HA) and gelatin-based hydrogel system comprised of a multi-crosslinker, 2-stage crosslinking protocol, which can provide tissue specific biochemical signals and mimic the mechanical properties of in vivo tissues. Biochemical factors are provided by incorporating tissue-derived extracellular matrix materials, which include potent growth factors. Tissue mechanical properties are controlled combinations of PEG-based crosslinkers with varying molecular weights, geometries (linear or multi-arm), and functional groups to yield extrudable bioinks and final construct shear stiffness values over a wide range (100 Pa to 20 kPa). Using these parameters, hydrogel bioinks were used to bioprint primary liver spheroids in a liver-specific bioink to create in vitro liver constructs with high cell viability and measurable functional albumin and urea output. This methodology provides a general framework that can be adapted for future customization of hydrogels for biofabrication of a wide range of tissue construct types.
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- 2016
14. Human Inferior Turbinate
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Jeong-Hun Park, Su Young Kim, Sung Won Kim, Sun Hwa Park, Young-Joon Seol, Oak Kee Hong, Hyun Wook Kang, Mi Young Choi, Se Hwan Hwang, Dong-Woo Cho, and J.G. Rha
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Pathology ,medicine.medical_specialty ,Stromal cell ,Tissue Engineering ,Reverse Transcriptase Polymerase Chain Reaction ,business.industry ,Multipotent Stem Cells ,Cellular differentiation ,Blotting, Western ,Mesenchymal stem cell ,CD34 ,Cell Differentiation ,Mesenchymal Stem Cells ,Flow Cytometry ,Turbinates ,Otorhinolaryngology ,Tissue engineering ,Multipotent Stem Cell ,Humans ,Medicine ,Immunohistochemistry ,Surgery ,Progenitor cell ,business - Abstract
Mesenchymal stromal cells (MSCs) are multipotent progenitor cells in adult tissues. Current challenges for the clinical application of MSCs include donor site morbidity, which underscores the need to identify alternative sources of MSCs. This study aimed to explore potential new sources of multipotent MSCs for use in tissue regeneration and the functional restoration of organs.Mixed methods research.Tertiary care center.The authors isolated MSCs from human inferior turbinate tissues discarded during turbinate surgery of 10 patients for nasal obstruction. The expression of surface markers for MSCs was assessed by fluorescence-activated cell sorting. The differentiation potential of human turbinate mesenchymal stromal cells (hTMSCs) was analyzed by immunohistochemistry, reverse transcriptase-polymerase chain reaction, and Western blot analysis.Surface epitope analysis revealed that hTMSCs were negative for CD14, CD19, CD34, and HLA-DR and positive for CD29, CD73, and CD90, representing a characteristic phenotype of MSCs. Extracellular matrices with characteristics of cartilage, bone, and adipose tissue were produced by inducing the chondrogenic, osteogenic, and adipogenic differentiation of hTMSCs, respectively. The expression of neuron-specific markers in hTMSCs was confirmed immunocytochemically.The hTMSCs represent a new source of multipotent MSCs that are potentially applicable to tissue engineering and regenerative medicine. The availability of differentiated adult cells will allow the development of an effective tissue regeneration method.
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- 2012
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15. Solid freeform fabrication technology applied to tissue engineering with various biomaterials
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Dong-Woo Cho, Tae-Yun Kang, and Young-Joon Seol
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Scaffold fabrication ,Scaffold ,Fabrication ,Tissue engineering ,Computer science ,parasitic diseases ,technology, industry, and agriculture ,Target tissue ,Nanotechnology ,Solid freeform fabrication ,General Chemistry ,Condensed Matter Physics ,Tissue volume - Abstract
An important component in tissue engineering is the three-dimensional (3D) scaffold, which guides cells to form target tissue, maintains tissue volume, and provides sufficient structural support during tissue regeneration. However, until recently, conventional scaffold fabrication methods have not satisfied the requirements for tissue regeneration. The development of additive fabrication technologies, known as solid freeform fabrication (SFF), has made it possible to fabricate scaffolds with very fine structures and complex geometries using computer-aided design (CAD) data acquired from medical images of patients. Due to the advantages of SFF technology, it is rapidly becoming the technique of choice for scaffold fabrication. Moreover, recent research has demonstrated that a variety of biomaterials are suitable for use in various SFF systems. This paper reviews the application, advancement, and potential of SFF technologies in the fabrication of scaffolds for tissue regeneration.
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- 2012
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16. Fabrication of Calcium Phosphate Scaffolds Using Projection-based Microstereolithography and Their Effects on Osteogenesis
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Ju-Young Park, Dong-Woo Cho, and Young-Joon Seol
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Scaffold ,Materials science ,Fabrication ,Mechanical Engineering ,Regeneration (biology) ,technology, industry, and agriculture ,Sintering ,chemistry.chemical_element ,Solid freeform fabrication ,Calcium ,Bone tissue ,Synthetic polymer ,medicine.anatomical_structure ,chemistry ,medicine ,Biomedical engineering - Abstract
Calcium phosphates are very interesting materials for use as scaffolds for bone tissue engineering. These materials include hydroxyapatite (HA) and tricalcium phosphate (TCP), which are inorganic components of human bone tissue and are both biocompatible and osteoconductive. Although these materials have excellent properties for use as bone scaffolds, many researchers have used these materials as additives to synthetic polymer scaffolds for bone tissue regeneration, because they are difficult to manufacture three-dimensional (3D) scaffolds. In this study, we fabricated 3D calcium phosphate scaffolds with the desired inner and outer architectures using solid freeform fabrication technology. To fabricate the scaffold, the sintering behavior was evaluated for various sintering temperatures and slurry concentrations. After the fabrication of the calcium phosphate scaffolds, in-vitro cell proliferation and osteogenic differentiation tests were carried out.
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- 2011
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17. Fabrication of a hydroxyapatite scaffold for bone tissue regeneration using microstereolithography and molding technology
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Shin-Yoon Kim, Jong Young Kim, Dong-Woo Cho, Eui Kyun Park, and Young-Joon Seol
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Pore size ,Scaffold ,Fabrication ,Materials science ,Manufacturing process ,Regeneration (biology) ,technology, industry, and agriculture ,Molding (process) ,Condensed Matter Physics ,Bone tissue ,Atomic and Molecular Physics, and Optics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,medicine.anatomical_structure ,law ,parasitic diseases ,medicine ,Electrical and Electronic Engineering ,Stereolithography ,Biomedical engineering - Abstract
Recently, many groups have researched the reconstruction of bone tissue and the development of bone scaffolds using solid freeform fabrication technology. However, the capacity to produce three-dimensional hydroxyapatite (HA) scaffolds with a very accurate architecture is limited by difficulties in the manufacturing process. In this study, a HA scaffold with an accurate pore size of 300+/[email protected] was fabricated using a microstereolithography (MSTL) system and molding technology. In addition, an agar-overlay test was performed to investigate the cytotoxicity of the fabricated scaffold.
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- 2009
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18. List of Contributors
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Kenichi Arai, Anthony Atala, Rashid Bashir, Danielle Beski, Jonathan T. Butcher, Hyung-Gi Byun, James K. Carrow, Sylvain Catros, Daniel Y.C. Cheung, Dong-Woo Cho, David Dean, Aurora De Acutis, Carmelo De Maria, Bin Duan, Tom Dufour, John P. Fisher, Colleen L. Flanagan, Gabor Forgacs, Jean-Christophe Fricain, Akhilesh K. Gaharwar, Frederik Gelaude, Glenn E. Green, Fabien Guillemot, Scott J. Hollister, James B. Hoying, Jeung Soo Huh, Ashok Ilankovan, Shintaroh Iwanaga, Manish K. Jaiswal, Jinah Jang, Hyun-Wook Kang, Carlos Kengla, Punyavee Kerativitayanan, Virginie Keriquel, Maryna Kvasnytsia, Joseph M. Labuz, Kuilin Lai, Michael Larsen, Hui Chong Lau, Mike Lawrenchuk, Jin Woo Lee, Sang Jin Lee, Brendan M. Leung, Grace J. Lim, Giriraj Lokhande, Ihor Lukyanenko, Julie Marco, Francoise Marga, Anthony J. Melchiorri, Tyler K. Merceron, Michael Miller, Mariam Mir, Ruchi Mishra, Christopher Moraes, Lorenzo Moroni, Robert J. Morrison, Carlos Mota, Sean V. Murphy, Makoto Nakamura, Hassan Nasser, Lars Neumann, Anthony Nguyen, Christopher Owens, Falguni Pati, Steve Pentoney, Sharon Presnell, Ritu Raman, Kristina Roskos, Emilie Sauvage, Young-Joon Seol, Aleksander Skardal, Ana Soares, Ingrid Stuiver, Shuichi Takayama, Katrien Vanderperren, Dieter Vangeneugden, Giovanni Vozzi, Matthew B. Wheeler, Stuart K. Williams, Tao Xu, James J. Yoo, and David A. Zopf
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- 2015
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19. Bioprinting of Three-Dimensional Tissues and Organ Constructs
- Author
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Anthony Atala, James J. Yoo, and Young-Joon Seol
- Subjects
Engineering ,Tissue engineering ,business.industry ,Nanotechnology ,business ,Regenerative medicine ,Organ regeneration - Abstract
Three-dimensional (3D) bioprinting technology has been utilized as a method to engineer complex tissues and organs. This rapidly growing technology allows for precise placement of multiple types of cells, biomaterials, and biomolecules in spatially predefined locations within 3D structures. Many researchers are focusing on the further development of bioprinting technology and its applications. In this chapter, we introduce the general principles and limitations of widely used bioprinting systems and applications for tissue and organ regeneration. In addition, the current challenges facing the clinical applications of bioprinting technology are addressed.
- Published
- 2015
- Full Text
- View/download PDF
20. Improvement of bone regeneration capability of ceramic scaffolds by accelerated release of their calcium ions
- Author
-
Young-Joon Seol, Sung Won Kim, Jin Woo Jung, Dong-Woo Cho, Jinah Jang, Ju Young Park, and Rijal Girdhari
- Subjects
Male ,Ceramics ,Bone Regeneration ,Biomedical Engineering ,chemistry.chemical_element ,Bioengineering ,Calcium ,Bone tissue ,Prosthesis Design ,Biochemistry ,Ectopic bone formation ,Biomaterials ,Rats, Sprague-Dawley ,Materials Testing ,medicine ,Animals ,Bone formation ,Ceramic ,Bone regeneration ,Manufacturing technology ,Skull Fractures ,Tissue Scaffolds ,Guided Tissue Regeneration ,Regeneration (biology) ,Original Articles ,Rats ,Equipment Failure Analysis ,medicine.anatomical_structure ,Treatment Outcome ,chemistry ,visual_art ,Bone Substitutes ,visual_art.visual_art_medium ,Biomedical engineering - Abstract
To regenerate the bone tissue, the fabrication of scaffolds for better tissue regeneration has attracted a great deal of attention. In fact, growth factors are already used in clinical practice and are being investigated for enhancing the capacity for bone tissue regeneration. However, despite their strong osteoinductive activity, these growth factors have several limitations: safety issues, high treatment costs, and the potential for ectopic bone formation. The aim of this study was therefore to develop ceramic scaffolds that could promote the capacity for bone regeneration without growth factors. Three-dimensional ceramic scaffolds were successfully fabricated from hydroxyapatite (HA) and tricalcium phosphate (TCP) using projection-based microstereolithography, which is an additive manufacturing technology. The effects of calcium ions released from ceramic scaffolds on osteogenic differentiation and bone regeneration were evaluated in vitro and in vivo. The osteogenesis-related gene expression and area of new bone formation in the HA/TCP scaffolds was higher than those in the HA scaffolds. Moreover, regenerated bone tissue in HA/TCP scaffolds were more matured than that in HA scaffolds. Through this study, we were able to enhance the bone regeneration capacity of scaffolds not by growth factors but by calcium ions released from the scaffolds. Ceramic scaffolds developed in this study might be useful for enhancing the capacity for regeneration in complex bone defects.
- Published
- 2014
21. Effects of alginate hydrogel cross-linking density on mechanical and biological behaviors for tissue engineering
- Author
-
Dong-Woo Cho, Joydip Kundu, Jinah Jang, Young-Joon Seol, Hyeon Ji Kim, and Sung Won Kim
- Subjects
Pore size ,Morphology (linguistics) ,Materials science ,Alginates ,Biomedical Engineering ,Biocompatible Materials ,Calcium Carbonate ,Biomaterials ,chemistry.chemical_compound ,Chondrocytes ,Tissue engineering ,Rheology ,Glucuronic Acid ,Humans ,Aggrecan ,Mechanical Phenomena ,Tissue Engineering ,Tissue Scaffolds ,Hexuronic Acids ,Hydrogels ,Chondrogenesis ,Biomechanical Phenomena ,Extracellular Matrix ,Calcium carbonate ,chemistry ,Mechanics of Materials ,Biophysics ,Alginate hydrogel ,Biomedical engineering - Abstract
An effective cross-linking of alginate gel was made through reaction with calcium carbonate (CaCO3). We used human chondrocytes as a model cell to study the effects of cross-linking density. Three different pore size ranges of cross-linked alginate hydrogels were fabricated. The morphological, mechanical, and rheological properties of various alginate hydrogels were characterized and responses of biosynthesis of cells encapsulated in each gel to the variation in cross-linking density were investigated. Desired outer shape of structure was maintained when the alginate solution was cross-linked with the applied method. The properties of alginate hydrogel could be tailored through applying various concentrations of CaCO3. The rate of synthesized GAGs and collagens was significantly higher in human chondrocytes encapsulated in the smaller pore structure than that in the larger pore structure. The expression of chondrogenic markers, including collagen type II and aggrecan, was enhanced in the smaller pore structure. It was found that proper structural morphology is a critical factor to enhance the performance and tissue regeneration.
- Published
- 2014
22. Erratum to: Development and analysis of three-dimensional (3D) printed biomimetic ceramic ossicles
- Author
-
Sung Won Kim, Min Sung, Wonkyu Moon, Jung-Seob Lee, Jeong-Hoon Oh, Young-Joon Seol, and Dong-Woo Cho
- Subjects
3d printed ,medicine.anatomical_structure ,Materials science ,Ossicles ,Mechanical Engineering ,visual_art ,medicine ,visual_art.visual_art_medium ,Nanotechnology ,Ceramic ,Electrical and Electronic Engineering ,Industrial and Manufacturing Engineering ,Biomedical engineering - Abstract
The online version of the original article can be found at http://dx.doi.org/10.1007/s12541-016-0198-2
- Published
- 2017
- Full Text
- View/download PDF
23. Three-Dimensional Bioprinting of Muscle Constructs for Reconstruction
- Author
-
John D. Jackson, Young-Joon Seol, Hyun Wook Kang, James J. Yoo, Sang Jin Lee, Anthony Atala, In Kap Ko, and Ji Hyun Kim
- Subjects
business.industry ,Medicine ,Surgery ,business ,Biomedical engineering - Published
- 2016
- Full Text
- View/download PDF
24. A new method of fabricating robust freeform 3D ceramic scaffolds for bone tissue regeneration
- Author
-
Seong Jin Park, Young-Joon Seol, Dong-Woo Cho, Dong Yong Park, Ju Young Park, and Sung Won Kim
- Subjects
Scaffold ,Toughness ,Ceramics ,Materials science ,Bone Regeneration ,Bioengineering ,Nanotechnology ,Bone tissue ,Applied Microbiology and Biotechnology ,chemistry.chemical_compound ,Tissue engineering ,Osteogenesis ,medicine ,Humans ,Ceramic ,Cells, Cultured ,Cell Proliferation ,Analysis of Variance ,Tissue Engineering ,Tissue Scaffolds ,Regeneration (biology) ,Compressive strength ,medicine.anatomical_structure ,chemistry ,visual_art ,Polycaprolactone ,Bone Substitutes ,visual_art.visual_art_medium ,Biotechnology - Abstract
Fabrication of three-dimensional (3D) scaffolds with appropriate mechanical properties and desired architecture for promoting cell growth and new tissue formation is one of the most important efforts in tissue engineering field. Scaffolds fabricated from bioactive ceramic materials such as hydroxyapatite and tricalcium phosphate show promise because of their biological ability to support bone tissue regeneration. However, the use of ceramics as scaffold materials is limited because of their inherent brittleness and difficult processability. The aim of this study was to create robust ceramic scaffolds, which have a desired architecture. Such scaffolds were successfully fabricated by projection-based microstereolithography, and dilatometric analysis was conducted to study the sintering behavior of the ceramic materials. The mechanical properties of the scaffolds were improved by infiltrating them with a polycaprolactone solution. The toughness and compressive strength of these ceramic/polymer scaffolds were about twice those of ceramic scaffolds. Furthermore, the osteogenic gene expression on ceramic/polymer scaffolds was better than that on ceramic scaffolds. Through this study, we overcame the limitations of previous research on fabricating ceramic scaffolds and these new robust ceramic scaffolds may provide a much improved 3D substrate for bone tissue regeneration.
- Published
- 2012
25. Short-term evaluation of electromagnetic field pretreatment of adipose-derived stem cells to improve bone healing
- Author
-
Kyung Shin, Kang, Jung Min, Hong, Young-Joon, Seol, Jong-Won, Rhie, Young Hun, Jeong, and Dong-Woo, Cho
- Subjects
Fracture Healing ,Male ,Mice ,Mice, Inbred BALB C ,Electromagnetic Fields ,Adipose Tissue ,Cell Transplantation ,Stem Cells ,Animals ,Humans ,Cells, Cultured ,Signal Transduction - Abstract
An electromagnetic field is an effective stimulation tool because it promotes bone defect healing, albeit in an unknown way. Although electromagnetic fields are used for treatment after surgery, many patients prefer cell-based tissue regeneration procedures that do not require daily treatments. This study addressed the effects of an electromagnetic field on adipose-derived stem cells (ASCs) to investigate the feasibility of pretreatment to accelerate bone regeneration. After identifying a uniform electromagnetic field inside a solenoid coil, we observed that a 45 Hz electromagnetic field induced osteogenic marker expression via bone morphogenetic protein, transforming growth factor β, and Wnt signalling pathways based on microarray analyses. This electromagnetic field increased osteogenic gene expression, alkaline phosphate activity and nodule formation in vitro within 2 weeks, indicating that this pretreatment may provide osteogenic potential to ASCs on three-dimensional (3D) ceramic scaffolds. This pretreatment effect of an electromagnetic field resulted in significantly better bone regeneration in a mouse calvarial defect model over 4 weeks compared to that in the untreated group. This short-term evaluation showed that the electromagnetic field pretreatment may be a future therapeutic option for bone defect treatment.
- Published
- 2012
26. Unit cell-based computer-aided manufacturing system for tissue engineering
- Author
-
Tae-Yun Kang, Jeong-Hun Park, Dong-Woo Cho, Hyun Wook Kang, and Young-Joon Seol
- Subjects
Models, Anatomic ,Engineering drawing ,Scaffold ,Engineering ,Fabrication ,Surface Properties ,Biomedical Engineering ,Mechanical engineering ,Bioengineering ,computer.software_genre ,Biochemistry ,GeneralLiterature_MISCELLANEOUS ,Biomaterials ,Software ,Tissue engineering ,Computer Aided Design ,Humans ,Tissue Engineering ,Tissue Scaffolds ,business.industry ,technology, industry, and agriculture ,Process (computing) ,General Medicine ,Data structure ,Spine ,Computer-aided manufacturing ,Computer-Aided Design ,business ,computer ,Porosity ,Tooth ,Algorithms ,Biotechnology - Abstract
Scaffolds play an important role in the regeneration of artificial tissues or organs. A scaffold is a porous structure with a micro-scale inner architecture in the range of several to several hundreds of micrometers. Therefore, computer-aided construction of scaffolds should provide sophisticated functionality for porous structure design and a tool path generation strategy that can achieve micro-scale architecture. In this study, a new unit cell-based computer-aided manufacturing (CAM) system was developed for the automated design and fabrication of a porous structure with micro-scale inner architecture that can be applied to composite tissue regeneration. The CAM system was developed by first defining a data structure for the computing process of a unit cell representing a single pore structure. Next, an algorithm and software were developed and applied to construct porous structures with a single or multiple pore design using solid freeform fabrication technology and a 3D tooth/spine computer-aided design model. We showed that this system is quite feasible for the design and fabrication of a scaffold for tissue engineering.
- Published
- 2012
27. Development of 3D PPF/DEF scaffolds using micro-stereolithography and surface modification
- Author
-
Dong-Woo Cho, Phung Xuan Lan, Jin Woo Lee, and Young-Joon Seol
- Subjects
Scaffold ,Materials science ,Surface Properties ,Simulated body fluid ,Biomedical Engineering ,Biophysics ,Bioengineering ,Biocompatible Materials ,engineering.material ,Polypropylenes ,Apatite ,Biomaterials ,Mice ,Coating ,Tissue engineering ,Fumarates ,Biomimetic Materials ,Apatites ,Materials Testing ,Animals ,Bone regeneration ,Tissue Engineering ,Tissue Scaffolds ,3T3 Cells ,Biodegradable polymer ,Cross-Linking Reagents ,visual_art ,engineering ,visual_art.visual_art_medium ,Microscopy, Electron, Scanning ,Surface modification ,Oligopeptides ,Biomedical engineering - Abstract
Poly(propylene fumarate) (PPF) is an ultraviolet-curable and biodegradable polymer with potential applications for bone regeneration. In this study, we designed and fabricated three-dimensional (3D) porous scaffolds based on a PPF polymer network using micro-stereolithography (MSTL). The 3D scaffold was well fabricated with a highly interconnected porous structure and porosity of 65%. These results provide a new scaffold fabrication method for tissue engineering. Surface modification is a commonly used and effective method for improving the surface characteristics of biomaterials without altering their bulk properties that avoids the expense and long time associated with the development of new biomaterials. Therefore, we examined surface modification of 3D scaffolds by applying accelerated biomimetic apatite and arginine-glycine-aspartic acid (RGD) peptide coating to promote cell behavior. The apatite coating uniformly covered the scaffold surface after immersion for 24 h in 5-fold simulated body fluid (5SBF) and then the RGD peptide was applied. Finally, the coated 3D scaffolds were seeded with MC3T3-E1 pre-osteoblasts and their biologic properties were evaluated using an MTS assay and histologic staining. We found that 3D PPF/diethyl fumarate (DEF) scaffolds fabricated with MSTL and biomimetic apatite coating can be potentially used in bone tissue engineering.
- Published
- 2008
28. A 3D bioprinted complex structure for engineering the muscle–tendon unit
- Author
-
Hyun Wook Kang, Anthony Atala, Sang Jin Lee, James J. Yoo, Tyler K. Merceron, Young-Joon Seol, and Morgan Burt
- Subjects
Materials science ,Cell Survival ,Biomedical Engineering ,Biocompatible Materials ,Bioengineering ,Biochemistry ,Cell Line ,Biomaterials ,Mice ,Thermoplastic polyurethane ,Tissue scaffolds ,Tissue engineering ,medicine ,Animals ,Cell survival ,Tissue Engineering ,Tissue Scaffolds ,Bioprinting ,technology, industry, and agriculture ,Stiffness ,General Medicine ,musculoskeletal system ,Biocompatible material ,Tendon ,medicine.anatomical_structure ,Printing, Three-Dimensional ,medicine.symptom ,Regional differences ,Biotechnology ,Biomedical engineering - Abstract
Three-dimensional integrated organ printing (IOP) technology seeks to fabricate tissue constructs that can mimic the structural and functional properties of native tissues. This technology is particularly useful for complex tissues such as those in the musculoskeletal system, which possess regional differences in cell types and mechanical properties. Here, we present the use of our IOP system for the processing and deposition of four different components for the fabrication of a single integrated muscle-tendon unit (MTU) construct. Thermoplastic polyurethane (PU) was co-printed with C2C12 cell-laden hydrogel-based bioink for elasticity and muscle development on one side, while poly(ϵ-caprolactone) (PCL) was co-printed with NIH/3T3 cell-laden hydrogel-based bioink for stiffness and tendon development on the other. The final construct was elastic on the PU-C2C12 muscle side (E = 0.39 ± 0.05 MPa), stiff on the PCL-NIH/3T3 tendon side (E = 46.67 ± 2.67 MPa) and intermediate in the interface region (E = 1.03 ± 0.14 MPa). These constructs exhibited >80% cell viability at 1 and 7 d after printing, as well as initial tissue development and differentiation. This study demonstrates the versatility of the IOP system to create integrated tissue constructs with region-specific biological and mechanical characteristics for MTU engineering.
- Published
- 2015
- Full Text
- View/download PDF
29. Development of an indirect solid freeform fabrication process based on microstereolithography for 3D porous scaffolds
- Author
-
Hyun Wook Kang, Young-Joon Seol, and Dong-Woo Cho
- Subjects
chemistry.chemical_classification ,Scaffold ,Materials science ,Mechanical Engineering ,Nanotechnology ,Molding (process) ,Polymer ,medicine.disease_cause ,Electronic, Optical and Magnetic Materials ,law.invention ,chemistry.chemical_compound ,Photopolymer ,chemistry ,Mechanics of Materials ,law ,Mold ,Polycaprolactone ,medicine ,Electrical and Electronic Engineering ,Composite material ,Porosity ,Stereolithography - Abstract
Scaffold fabrication using solid freeform fabrication (SFF) technology is a hot topic in tissue engineering. Here, we present a new indirect SFF technology based on microstereolithography (MSTL), which has the highest resolution of all SFF methods, to construct a three-dimensional (3D) porous scaffold by combining SFF with molding technology. To realize this indirect method, we investigated and modified a water-soluble photopolymer. We used MSTL technology to fabricate a high-resolution 3D porous mold composed of the modified polymer. The mold can be removed using an appropriate solvent. We tested two materials, polycaprolactone and calcium sulfate hemihydrate, using the molding process, and developed a lost-mold shape forming process by dissolving the mold. This procedure demonstrated that the proposed method can yield scaffold pore sizes as small as 60–70 µm. In addition, cytotoxicity test results indicated that the proposed process is feasible for producing 3D porous scaffolds.
- Published
- 2008
- Full Text
- View/download PDF
30. Effects of alginate hydrogel cross-linking density on mechanical and biological behaviors for tissue engineering.
- Author
-
Jinah Jang, Young-Joon Seol, Hyeon Ji Kim, Joydip Kundu, Sung Won Kim, and Dong-Woo Cho
- Subjects
ALGINATES ,TISSUE engineering ,CALCIUM carbonate ,CARTILAGE cells ,BIOSYNTHESIS - Abstract
An effective cross-linking of alginate gel was made through reaction with calcium carbonate (CaCO
3 ). We used human chondrocytes as a model cell to study the effects of cross-linking density. Three different pore size ranges of cross-linked alginate hydrogels were fabricated. The morphological, mechanical, and rheological properties of various alginate hydrogels were characterized and responses of biosynthesis of cells encapsulated in each gel to the variation in cross-linking density were investigated. Desired outer shape of structure was maintained when the alginate solution was cross-linked with the applied method. The properties of alginate hydrogel could be tailored through applying various concentrations of CaCO3 . The rate of synthesized GAGs and collagens was significantly higher in human chondrocytes encapsulated in the smaller pore structure than that in the larger pore structure. The expression of chondrogenic markers, including collagen type II and aggrecan, was enhanced in the smaller pore structure. It was found that proper structural morphology is a critical factor to enhance the performance and tissue regeneration. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
31. Development of 3D PPF/DEF scaffolds using micro-stereolithography and surface modification.
- Author
-
Phung Xuan Lan, Jin Woo Lee, Young-Joon Seol, and Dong-Woo Cho
- Subjects
BONE remodeling ,PROPENE ,PHOSPHATE minerals ,BIOMEDICAL materials ,APATITE ,POROUS materials ,BONE regeneration ,BIOMIMETIC chemicals ,REGENERATION (Biology) - Abstract
Poly(propylene fumarate) (PPF) is an ultraviolet-curable and biodegradable polymer with potential applications for bone regeneration. In this study, we designed and fabricated three-dimensional (3D) porous scaffolds based on a PPF polymer network using micro-stereolithography (MSTL). The 3D scaffold was well fabricated with a highly interconnected porous structure and porosity of 65%. These results provide a new scaffold fabrication method for tissue engineering. Surface modification is a commonly used and effective method for improving the surface characteristics of biomaterials without altering their bulk properties that avoids the expense and long time associated with the development of new biomaterials. Therefore, we examined surface modification of 3D scaffolds by applying accelerated biomimetic apatite and arginine-glycine-aspartic acid (RGD) peptide coating to promote cell behavior. The apatite coating uniformly covered the scaffold surface after immersion for 24 h in 5-fold simulated body fluid (5SBF) and then the RGD peptide was applied. Finally, the coated 3D scaffolds were seeded with MC3T3-E1 pre-osteoblasts and their biologic properties were evaluated using an MTS assay and histologic staining. We found that 3D PPF/diethyl fumarate (DEF) scaffolds fabricated with MSTL and biomimetic apatite coating can be potentially used in bone tissue engineering. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
32. A 3D bioprinted complex structure for engineering the muscle–tendon unit.
- Author
-
Tyler K Merceron, Morgan Burt, Young-Joon Seol, Hyun-Wook Kang, Sang Jin Lee, James J Yoo, and Anthony Atala
- Published
- 2015
- Full Text
- View/download PDF
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