Introduction: Bone fractures are a global public health burden as there are more than 150 million bone fracture incidence per year. The therapeutic effect of mesenchymal stem cells (MSCs) is mediated by the secretion and release of trophic molecules, which are called ‘secretome'. There are only a handful of studies that evaluated the effect of dental MSCs-derived secretome in bone healing and regeneration.
Aim of Study: This study was designed to investigate the regenerative potential of human dental pulp stem cells' (hDPSCs') secretome on rabbits' tibial bone defects at three- and six-weeks follow-ups.
Materials and Methods: 42 rabbits received 84 six-mm-diameter tibial bone defects; 21 for each outcome; 7 defects for each group per each time interval. Bone defects were either left to heal spontaneously (Group A) or received either collagen scaffold (Group B) or hDPSCs' secretome loaded on collagen scaffold (Group C). Animals were euthanized at three and six weeks. Histomorphometric evaluation of newly formed bone area percent and degree of bone maturation using Hematoxylin and Eosin (H&E) and Masson Trichrome (MT) stains respectively was constructed in addition to quantitative real time polymerase chain reaction (qRT-PCR) to evaluate osteocalcin levels.
Results: Histomorphometric analysis of H&E- & MT- stained sections showed significant increase in bone area percent as well as bone maturation in the group C in comparison to the other two groups (P < 0.05) at both time intervals. qRT-PCR results supported our abovementioned results as they showed that osteocalcin levels were higher in group C as compared to the other two groups at both time intervals (P <0.05).
Conclusions: hDPSCs' secretome showed superior results and significant improvement of bone healing.