title: Primary human alveolar bone cells isolated from tissue samples acquired at periodontal surgeries exhibit sustained proliferation and retain osteogenic phenotype during in vitro expansion.
abstract: OBJECTIVE
  Bone tissue regeneration requires a source of viable, proliferative cells with osteogenic differentiation capacity. Periodontal surgeries represent an opportunity to procure small amounts of autologous tissues for primary cell isolation. Our objective was to assess the potential of human alveolar bone as a source of autologous osteogenic cells for tissue engineering and biomaterials and drug testing studies.
  
  
  METHODS
  Alveolar bone tissue was obtained from 37 patients undergoing routine periodontal surgery. Tissue harvesting and cell isolation procedures were optimized to isolate viable cells. Primary cells were subcultured and characterized with respect to their growth characteristics, gene expression of osteogenic markers, alkaline phosphatase activity and matrix mineralization, under osteogenic stimulation.
  
  
  RESULTS
  Alveolar bone cells were successfully isolated from 28 of the 30 samples harvested with bone forceps, and from 2 of the 5 samples obtained by bone drilling. The yield of cells in primary cultures was variable between the individual samples, but was not related to the site of tissue harvesting and the patient age. In 80% of samples (n = 5), the primary cells proliferated steadily for eight subsequent passages, reaching cumulative numbers over 10(10) cells. Analyses confirmed stable gene expression of alkaline phosphatase, osteopontin and osteocalcin in early and late cell passages. In osteogenic medium, the cells from late passages increased alkaline phosphatase activity and accumulated mineralized matrix, indicating a mature osteoblastic phenotype.
  
  
  CONCLUSIONS
  Primary alveolar bone cells exhibited robust proliferation and retained osteogenic phenotype during in vitro expansion, suggesting that they can be used as an autologous cell source for bone regenerative therapies and various in vitro studies.
authors.affiliation: Blood Transfusion Center of Slovenia, Ljubljana, Slovenia; Educell d.o.o., Trzin, Slovenia.
authors.forename: Darja
authors.initials: D
authors.lastname: Marolt
authors.affiliation: Community Health Center, Ljubljana, Slovenia.
authors.forename: Matjaz
authors.initials: M
authors.lastname: Rode
authors.affiliation: Educell d.o.o., Trzin, Slovenia; Faculty of Health Sciences, Novo mesto, Slovenia.
authors.forename: Nevenka
authors.initials: N
authors.lastname: Kregar-Velikonja
authors.affiliation: Blood Transfusion Center of Slovenia, Ljubljana, Slovenia; Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia; Celica d.o.o. Biomedical Centre, Ljubljana, Slovenia.
authors.forename: Matjaz
authors.initials: M
authors.lastname: Jeras
authors.affiliation: Blood Transfusion Center of Slovenia, Ljubljana, Slovenia; Educell d.o.o., Trzin, Slovenia.
authors.forename: Miomir
authors.initials: M
authors.lastname: Knezevic
mesh_terms: D000328:Adult; D000368:Aged; D000539:Alveolar Process / Q000166:cytology* / Q000502:physiology*; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D049109:Cell Proliferation; D002469:Cell Separation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019647:Oral Surgical Procedures; D010012:Osteogenesis; D010641:Phenotype; D012038:Regeneration; D023822:Tissue Engineering; D055815:Young Adult