טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentBendalak Hila
SubjectAutologous Adipose TDssue Derived MSCs for the Treatment
of an Alveolar Defect Rat Model
DepartmentDepartment of Medicine
Supervisor Clinical Professor Dror Aizenbud


Abstract

Cleft lip and palate is caused by abnormal facial development during gestation. The reported incidence in the Mediterranean region and in Israel is 1:700.  One of the important steps in the treatment protocol is bone grafting.

The use of autogenous and alloplastic bone grafting materials has been studied. Autogenous cancellous bone harvested from the iliac crest is considered the "gold standard" grafting procedure. The main drawback of the procedure is the postoperative pain resulting in morbidity and even mortality. Minimally invasive alternative techniques for autogenous bone substitutes may include stem cell therapy.

Stem cell therapy is evolving as a groundbreaking treatment of diseases and injury, also involved congenital and acquired bone defects of the jaws.

There are various sources for MSCs. Adipose tissue derived MSCs are capable to differentiate into the osteogenic lineage and are continuously studied due to the ability to regenerate bone in vivo. Moreover, adipose tissue represents an abundant source of cells easy to obtain.

This work presents the implementation of Human Adipose tissue derived Mesenchymal Stem Cells (hASCs) as bone graft for the treatment of cleft lip and palate bone defect, along with the potential application of tissue engineering techniques to overcome the limitations of the available grafts used nowadays.

This study was based on a former project of this group which characterized the 3-dimensional [3D] mineral particle scaffold graft material and the in-vitro behavior of the hASCs seeded and cultured on this scaffold.

Our group had developed 3-dimensional [3D] mineral particle scaffold graft material in in-vitro settings.

The goal of this work was to investigate whether the implantation of "Injectable Bone" comprised of hASCs seeded mineral scaffold in a "Gel like" consistency into an alveolar bone cleft defect in a rat model, may induce bone regeneration resulting in alveolar cleft defects repair.

  A Critical-size alveolar cleft defect model was surgically developed in a rat. Treatment sub-groups included empty alveolar cleft defect - negative Control Defect only, mineralized cortical bone implantation - Cell-free scaffold and mineralized cortical bone scaffold, Cell-seeded scaffold with hASCs implantation.

Bone volume fraction (BV/TV) was characterized using µCT evaluation model. µCT revealed bone gain, though the quantitative measurement of bone volume did not demonstrate a statistically significant difference.  New bone formation was further correlated with histological and immunohistochemical analysis.  The level of bone area organization and maturation were further evaluated using polarized light microscopy. H&E sections were imaged and the suspected 'New Bone' orientation areas were evaluated indexed and proved. Than the 'New Bone' areas were transformed from their space into their frequency domains, using Fast Fourier Transform (FFT) algorithm demonstrated a statistically significant difference.

Our results suggest a surgical alveolar bone cleft model in combined with hASCs seeded on mineral scaffold to treat cleft palate bone defects. Further research is required to examine bone formation potential by these cells in an animal model.