title: An approachable human adult stem cell source for hard-tissue engineering.
abstract: Stem cells were obtained from deciduous dental pulp of healthy subjects, aged 6-10 years. This stem cell population was cultured, expanded, and specifically selected, detecting using a FACsorter, c-kit, CD34, and STRO-1 antigen expression. Then, c-kit+/CD34+/STRO-1+ cells were replaced in the culture medium added of 20% FBS, leading to osteoblast differentiation. In fact, these cells, after a week, showed a large positivity for CD44, osteocalcin, and RUNX-2 markers. To achieve an adipocytic differentiation, cells, after sorting, were challenged with dexamethason 10(-8) mM in the same culture medium. To obtain myotube fusion, sorted cells were co-cultured in ATCC medium with mouse myogenic C2C12 cells and, after a week, human stem cell nuclei were found to be able to fuse, forming myotubes. Differentiated osteoblasts, as assessed by a large positivity to several specific antibodies, after 30 days of culture and already in vitro, started to secrete an extracellular mineralized matrix, which, 2 weeks later, built a considerable number of 3D woven bone samples, which showed a strong positivity to alkaline phosphatase (ALP), alizarin red, calcein, other than to specific antibodies. These bone samples, after in vivo transplantation into immunosuppressed rats, were remodeled in a lamellar bone containing entrapped osteocytes. Therefore, this study provides strong evidence that human deciduous dental pulp is an approachable "niche" of stromal stem cells, and that it is an ideal source of osteoblasts, as well as of mineralized tissue, ready for bone regeneration, transplantation, and tissue-based clinical therapies.
authors.affiliation: Dipartimento di Discipline Odontostomatologiche, Ortodontiche e Chirurgiche, Secondo Ateneo di Napoli, Napoli, Italy.
authors.forename: Gregorio
authors.initials: G
authors.lastname: Laino
authors.forename: Antonio
authors.initials: A
authors.lastname: Graziano
authors.forename: Riccardo
authors.initials: R
authors.lastname: d'Aquino
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Pirozzi
authors.forename: Vladimiro
authors.initials: V
authors.lastname: Lanza
authors.forename: Salvatore
authors.initials: S
authors.lastname: Valiante
authors.forename: Alfredo
authors.initials: A
authors.lastname: De Rosa
authors.forename: Fabio
authors.initials: F
authors.lastname: Naro
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Vivarelli
authors.forename: Gianpaolo
authors.initials: G
authors.lastname: Papaccio
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001857:Bone Matrix / Q000378:metabolism; D002478:Cells, Cultured; D002648:Child; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism; D003782:Dental Pulp / Q000166:cytology*; D005109:Extracellular Matrix / Q000378:metabolism*; D005260:Female; D006801:Humans; D016867:Immunocompromised Host; D008297:Male; D059630:Mesenchymal Stem Cells; D010006:Osteoblasts / Q000166:cytology / Q000201:enzymology; D010012:Osteogenesis; D051381:Rats; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000502:physiology*; D023822:Tissue Engineering; D014080:Tooth Exfoliation; D014094:Tooth, Deciduous / Q000166:cytology
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D000469:Alkaline Phosphatase