研究者詳細 - 丸尾　昭二

Hair regenerative medicine must involve practical procedures, such as cryopreservation of tissue grafts. This can aid in evaluating tissue safety and quality, as well as transportation to a clinic and multiple transplants. Hair follicle germs (HFGs), identified during in vivo development, are considered effective tissue grafts for hair regenerative medicine. However, to the best of our knowledge, methods for cryopreserving HFGs have not been explored yet. This study investigated the efficacy of slow vitrification methods for freezing HFGs. Cryoprotectants such as dimethyl sulfoxide (DMSO) and carboxylated poly-L-lysine were used for vitrification. The results indicate that DMSO vitrification yielded the most efficient de novo hair regeneration in mouse skin, comparable to that of non-cryoprotected HFGs. A microfinger was fabricated to scale up the cryopreservation method, considering that thousands of tissue grafts were required per patient in clinical practice. The microfinger can be used for a series of processes, holding the HFG, replacing it with a cryopreservation solution, freezing it in liquid nitrogen, thawing it in a warm medium, and transplanting it into the skin. Although de novo hair regeneration by HFGs cryopreserved using microfingers was reduced by approximately 20 % compared to those cryopreserved using flat plates for fertilized eggs, it exceeded 50 %. These findings demonstrate that vitrification with DMSO and microfingers could be a useful approach for the cryopreservation of tissue grafts in hair regenerative medicine for hair loss. (c) 2023, The Society for Biotechnology, Japan. All rights reserved.

On-Demand Tunability of Microphase Separation Structure of 3D Printing Material by Reversible Addition/Fragmentation Chain Transfer Polymerization

Mukai, M; Sato, M; Miyadai, W; Maruo, S

POLYMERS 15 ( 17 ) 2023年9月 [査読有り]

DOI Web of Science PubMed

記述言語：英語掲載種別：研究論文（学術雑誌）共著

Bone beads enveloped with vascular endothelial cells for bone regenerative medicine *

Kageyama Tatsuto, Akieda Hikaru, Sonoyama Yukie, Sato Ken, Yoshikawa Hiroshi, Isono Hitoshi, Hirota … 全著者表示

Acta Biomaterialia 165 168 - 179 2023年6月

CiNii Research

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Elsevier Science Ltd. 共著

The transplantation of pre-vascularized bone grafts is a promising strategy to improve the efficacy of engraftment and bone regeneration. We propose a hydrogel microbead-based approach for preparing vascularized and high-density tissue grafts. Mesenchymal stem cell-encapsulated collagen microgels (2 & mu;L), termed bone beads, were prepared through spontaneous constriction, which improved the density of the mesenchymal stem cells and collagen molecules by more than 15-fold from the initial day of culture. Constriction was attributed to cell-attractive forces and involved better osteogenic differentiation of mesenchymal stem cells than that of spheroids. This approach was scalable, and & SIM;20 0 0 bone beads were prepared semi-automatically using a liquid dispenser and spinner flask. The mechanical stimuli in the spinner flask further improved the osteogenic differentiation of the mesenchymal stem cells in the bone beads compared with that in static culture. Vascular endothelial cells readily attach to and cover the surface of bone beads. The in vitro assembly of the endothelial cell-enveloped bone beads resulted in microchannel formation in the interspaces between the bone beads. Significant effects of endothelialization on in vivo bone regeneration were shown in rats with cranial bone defects. The use of endothelialized bone beads may be a scalable and robust approach for treating large bone defects. A unique aspect of this study is that the hMSC-encapsulated collagen microgels were prepared through spontaneous constriction, leading to the enrichment of collagen and cell density. This constriction resulted in favorable microenvironments for the osteogenic differentiation of hMSCs, which is superior to conventional spheroid culture. The microgel beads were then enveloped with vascular endothelial cells and assembled to fabricate a tissue graft with vasculature in the interspaces among the beads. The significant effects of endothelialization on in vivo bone regeneration were clearly demonstrated in rats with cranial bone defects. We believe that microgel beads covered with vascular endothelial cells provide a promising approach for engineering better tissue grafts for bone-regenerative medicine.& COPY; 2022 The Author(s). Published by Elsevier Ltd on behalf of Acta Materialia Inc. This is an open access article under the CC BY licens ( http://creativecommons.org/licenses/by/4.0/ )

Gelatin acrylamide with improved UV crosslinking and mechanical properties for 3D biofabrication

Binbin Zhang Molino, Cathal O'Connell, Tatsuto Kageyama, Lei Yan, Yumeng Wu, Izuru Kawamura, Shoji … 全著者表示

Journal of Bioscience and Bioengineering 136 ( 1 ) 51 - 57 2023年4月 [査読有り]

DOI Web of Science PubMed CiNii Research

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Society for Biotechnology, Japan 共著

Photocrosslinkable gelatin has attracted increasing interest in the field of biofabrication, with the most studied and widely used photocrosslinkable gelatin being gelatin methacrylate (GelMa). However, the 3D fabrication of GelMa has presented several limitations and challenges, primarily due to its slow crosslinking speed. It is generally known that acryl-based functional groups have faster reaction kinetics than methacryl-base groups. However, gelatin acrylamide (GelAc) has not been widely investigated, largely due to its increased complexity of synthesis relative to GelMA. In this study, we developed a novel synthesis method for GelAc. By varying the reaction ratio of reagents, GelAc with a degree of substitution from 20% to 95% was produced. The UV crosslinking properties of GelAc was studied, demonstrating significantly faster crosslinking kinetics than GelMa, especially at lower concentrations and low photoinitiator concentrations. The swelling ratio and mechanical properties of the crosslinked GelAc hydrogel were also characterized, and biocompatibility experiments conducted via both surface seeding and hydrogel encapsulation of cells, with good cell viability observed. The application of GelAc for 3D biofabrication was demonstrated by 3D printing. GelAc can be a useful material for the fabrication of 3D conduits for tissue engineering applications. & COPY; 2023, The Society for Biotechnology, Japan. All rights reserved.

Fabrication of Flexible Wiring with Intrinsically Conducting Polymers Using Blue-Laser Microstereolithography

Mai Takenouchi, Masaru Mukai, Taichi Furukawa, Shoji Maruo

Polymers 14 ( 22 ) 4949 2022年11月 [査読有り]

DOI Web of Science PubMed

記述言語：英語掲載種別：研究論文（学術雑誌）共著

マイクロ・ナノ3Dプリンティング(<特集>超精密加工の最前線)

丸尾昭二

日本機械学会誌 125 ( 1247 ) 19 - 22 2022年10月

DOI CiNii Research

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人日本機械学会単著

Bone beads enveloped with vascular endothelial cells for bone regenerative medicine

Tatsuto Kageyama, Hikaru Akieda, Yukie Sonoyama, Ken Sato, Hiroshi Yoshikawa, Hitoshi Isono, Makoto … 全著者表示