title: Scaffold-free parathyroid tissue engineering using tonsil-derived mesenchymal stem cells.
abstract: To restore damaged parathyroid function, parathyroid tissue engineering is the best option. Previously, we reported that differentiated tonsil-derived mesenchymal stem cells (dTMSC) restore in vivo parathyroid function, but only if they are embedded in a scaffold. Because of the limited biocompatibility of Matrigel, however, here we developed a more clinically applicable, scaffold-free parathyroid regeneration system. Scaffold-free dTMSC spheroids were engineered in concave microwell plates made of polydimethylsiloxane in control culture medium for the first 7days and differentiation medium (containing activin A and sonic hedgehog) for next 7days. The size of dTMSC spheroids showed a gradual and significant decrease up to day 5, whereafter it decreased much less. Cells in dTMSC spheroids were highly viable (>80%). They expressed high levels of intact parathyroid hormone (iPTH), the parathyroid secretory protein 1, and cell adhesion molecule, N-cadherin. Furthermore, dTMSC spheroids-implanted parathyroidectomized (PTX) rats revealed higher survival rates (50%) over a 3-month period with physiological levels of both serum iPTH (57.7-128.2pg/mL) and ionized calcium (0.70-1.15mmol/L), compared with PTX rats treated with either vehicle or undifferentiated TMSC spheroids. This is the first report of a scaffold-free, human stem cell-based parathyroid tissue engineering and represents a more clinically feasible strategy for hypoparathyroidism treatment than those requiring scaffolds.
  
  
  CONCLUSIONS
  Herein, we have for the first time developed a scaffold-free parathyroid tissue spheroids using differentiated tonsil-derived mesenchymal stem cells (dTMSC) to restore in vivo parathyroid cell functions. This new strategy is effective, even for long periods (3months), and is thus likely to be more feasible in clinic for hypoparathyroidism treatment. Development of TMSC spheroids may also provide a convenient and efficient scaffold-free platform for researchers investigating conditions involving abnormal calcium homeostasis, such as osteoporosis.
authors.affiliation: Department of Molecular Medicine, School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea; Ewha Tonsil-derived mesenchymal Stem cells Research Center (ETSRC), School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea; School of Life Science, College of Natural Sciences, Chungbuk National University, Cheongju 361-763, Republic of Korea.
authors.forename: Yoon Shin
authors.initials: YS
authors.lastname: Park
authors.affiliation: Department of Biomedical Engineering, College of Health Science, Korea University, Seoul 136-713, Republic of Korea.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Hwang
authors.affiliation: Department of Biomedical Engineering, College of Health Science, Korea University, Seoul 136-713, Republic of Korea; KU-KIST Graduate School of Converging Science & Technology, Korea University, Seoul 136-713, Republic of Korea.
authors.forename: Yesl
authors.initials: Y
authors.lastname: Jun
authors.affiliation: Department of Molecular Medicine, School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea; Ewha Tonsil-derived mesenchymal Stem cells Research Center (ETSRC), School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea.
authors.forename: Yoon Mi
authors.initials: YM
authors.lastname: Jin
authors.affiliation: Department of Molecular Medicine, School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea; Ewha Tonsil-derived mesenchymal Stem cells Research Center (ETSRC), School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea.
authors.forename: Gyungah
authors.initials: G
authors.lastname: Kim
authors.affiliation: Department of Molecular Medicine, School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea; Ewha Tonsil-derived mesenchymal Stem cells Research Center (ETSRC), School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea.
authors.forename: Ha Yeong
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Ewha Tonsil-derived mesenchymal Stem cells Research Center (ETSRC), School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea; Department of Otorhinolaryngology - Head & Neck Surgery, School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea.
authors.forename: Han Su
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Biomedical Engineering, College of Health Science, Korea University, Seoul 136-713, Republic of Korea; KU-KIST Graduate School of Converging Science & Technology, Korea University, Seoul 136-713, Republic of Korea; Department of Bio-convergence Engineering, College of Health Science, Korea University, Seoul 136-713, Republic of Korea. Electronic address: dbiomed@korea.ac.kr.
authors.forename: Sang-Hoon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Molecular Medicine, School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea; Ewha Tonsil-derived mesenchymal Stem cells Research Center (ETSRC), School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea. Electronic address: inhojo@ewha.ac.kr.
authors.forename: Inho
authors.initials: I
authors.lastname: Jo
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001835:Body Weight; D015820:Cadherins / Q000378:metabolism; D002118:Calcium / Q000097:blood; D048430:Cell Shape; D048429:Cell Size; D002470:Cell Survival; D002648:Child; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D014066:Palatine Tonsil / Q000166:cytology*; D010280:Parathyroid Glands / Q000502:physiology* / Q000601:surgery; D010281:Parathyroid Hormone / Q000378:metabolism; D016105:Parathyroidectomy; D017207:Rats, Sprague-Dawley; D018874:Spheroids, Cellular / Q000166:cytology; D016019:Survival Analysis; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D015415:Biomarkers; D015820:Cadherins; D010281:Parathyroid Hormone; D002118:Calcium
keywords: Hypoparathyroidism; N-cadherin; Parathyroid hormone; Spheroid; Tonsil-derived mesenchymal stem cells