Bone Repair with Differentiated Osteoblasts from Adipose‑derived Stem Cells in Hydroxyapatite/Tricalcium Phosphate In vivo

Abstract

Background: Recently, tissue engineering has developed approaches for repair and restoration of damaged skeletal system based on different scaffolds and cells. This study evaluated the ability of differentiated osteoblasts from adipose‑derived stem cells (ADSCs) seeded into hydroxyapatite/
tricalcium phosphate (HA‑TCP) to repair bone.

Methods: In this study, ADSCs of 6 canines were seeded in HA‑TCP and differentiated into osteoblasts in osteogenic medium in vitro and bone markers evaluated by reverse transcription
polymerase chain reaction (RT‑PCR). Scanning electron microscopy (SEM) was applied for detection of cells in the pores of scaffold. HA‑TCP with differentiated cells as the test group and
without cells as the cell‑free group were implanted in separate defected sites of canine’s tibia. After 8 weeks, specimens were evaluated by histological, immunohistochemical methods, and
densitometry test. The data were analyzed using the SPSS 18 version software.

Results: The expression of Type I collagen and osteocalcin genes in differentiated cells were indicated by RT‑PCR. SEM results revealed the adhesion of cells in scaffold pores. Formation of trabecular bone confirmed by histological sections that revealed the thickness of bone trabecular was more in the test group. Production of osteopontin in extracellular matrix was indicated in both groups. Densitometry method indicated that strength in the test group was similar to cell‑free group and natural bone (P > 0.05).

Conclusions: This research suggests that ADSCs‑derived osteoblasts in HA‑TCP could be used for bone tissue engineering and repairing.

Keywords: Adipose‑derived stem cells, animal model, bone  repair, hydroxyapatite/tricalcium phosphate