Osteogenic potential of dental and oral derived stem cells in bone tissue engineering among animal models: An update.

Small bone defects can heal spontaneously through the bone modeling process due to their physiological environmental conditions. The bone modeling cycle preserves the reliability of the skeleton through the well-adjusted activities of its fundamental cell. Stem cells are a source of pluripotent cells with a capacity to differentiate into any tissue in the existence of a suitable medium. The concept of bone engineering is based on stem cells that can differentiate into bone cells. Mesenchymal stromal cells have been evaluated in bone tissue engineering due to their capacity to differentiate in osteoblasts. They can be isolated from bone marrow and from several adults oral and dental tissues such as permanent or deciduous teeth dental pulp, periodontal ligament, apical dental papilla, dental follicle precursor cells usually isolated from the follicle surrounding the third molar, gingival tissue, periosteum-derived cells, dental alveolar socket, and maxillary sinus Schneiderian membrane-derived cells. Therefore, a suitable animal model is a crucial step, as preclinical trials, to study the outcomes of mesenchymal cells on the healing of bone defects. We will discuss, through this paper, the use of mesenchymal stem cells obtained from several oral tissues mixed with different types of scaffolds tested in different animal models for bone tissue engineering. We will explore and link the comparisons between human and animal models and emphasized the factors that we need to take into consideration when choosing animals. The pig is considered as the animal of choice when testing large size and multiple defects for bone tissue engineering.

Comparing the osteogenic potential of schneiderian membrane and dental pulp mesenchymal stem cells: an in vitro study.

Mesenchymal stem cells, being characterized by high self-renewal capacity and multi-lineage differentiation potential, are widely used in regenerative medicine especially for repair of bone defects in patients with poor bone regenerative capacity. In this study, we aimed to compare the osteogenic potential of human maxillary schneiderian sinus membrane (hMSSM)-derived stem cells versus permanent teeth dental pulp stem cells (DPSCs). Both cells types were cultivated in osteogenic and non-osteogenic inductive media. Alkaline phosphatase (ALP) activity assay and quantitative real-time PCR analysis were carried out to assess osteogenic differentiation. We showed that ALP activity and osteoblastic markers transcription levels were more striking in hMSSM-derived stem cells than DPSCs. Our results highlight hMSSM-derived stem cells as a recommended stem cell type for usage during bone tissue regenerative therapy.

Healing of Bone Defects in Pig's Femur Using Mesenchymal Cells Originated from the Sinus Membrane with Different Scaffolds.

OBJECTIVE: Repairing bone defects, especially in older individuals with limited regenerative capacity, is still a big challenge. The use of biomimetic materials that can enhance the restoration of bone structure represents a promising clinical approach. In this study, we evaluated ectopic bone formation after the transplantation of human maxillary Schneiderian sinus membrane- (hMSSM-) derived cells embedded within various scaffolds in the femur of pigs. METHODS: The scaffolds used were collagen, gelatin, and hydroxyapatite/tricalcium phosphate (HA/ßTCP) where fibrin/thrombin was used as a control. Histological analysis was performed for the new bone formation. Quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC) were used to assess mRNA and protein levels of specific osteoblastic markers, respectively. RESULTS: Histological analysis showed that the three scaffolds we used can support new bone formation with a more pronounced effect observed in the case of the gelatin scaffold. In addition, mRNA levels of the different tested osteoblastic markers Runt-Related Transcription Factor 2 (RUNX-2), osteonectin (ON), osteocalcin (OCN), osteopontin (OPN), alkaline phosphatase (ALP), and type 1 collagen (COL1) were higher, after 2 and 4 weeks, in cell-embedded scaffolds than in control cells seeded within the fibrin/thrombin scaffold. Moreover, there was a very clear and differential expression of RUNX-2, OCN, and vimentin in osteocytes, osteoblasts, hMSSM-derived cells, and bone matrix. Interestingly, the osteogenic markers were more abundant, at both time points, in cell-embedded gelatin scaffold than in other scaffolds (collagen, HA/ßTCP, fibrin/thrombin). CONCLUSIONS: These results hold promise for the development of successful bone regeneration techniques using different scaffolds embedded with hMSSM-derived cells. This trial is registered with NCT02676921.

Evaluation of the Osteogenic Potential of Different Scaffolds Embedded with Human Stem Cells Originated from Schneiderian Membrane: An In Vitro Study.

BACKGROUND: Novel treatments for bone defects, particularly in patients with poor regenerative capacity, are based on bone tissue engineering strategies which include mesenchymal stem cells (MSCs), bioactive factors, and convenient scaffold supports. OBJECTIVE: In this study, we aimed at comparing the potential for different scaffolds to induce osteogenic differentiation of human maxillary Schneiderian sinus membrane- (hMSSM-) derived cells. Methods. hMSSM-derived cells were seeded on gelatin, collagen, or Hydroxyapatite ß-Tricalcium phosphate-Fibrin (Haß-TCP-Fibrin) scaffolds. Cell viability was determined using an MTT assay. Alizarin red staining method, Alkaline phosphatase (ALP) activity assay, and quantitative real-time PCR analysis were performed to assess hMSSM-derived cells osteogenic differentiation. RESULTS: Cell viability, calcium deposition, ALP activity, and osteoblastic markers transcription levels were most striking in gelatin scaffold-embedded hMSSM-derived cells. CONCLUSION: Our findings suggest a promising potential for gelatin-hMSSM-derived cell construct for treating bone defects.

Sinus Floor Augmentation With Ambient Blood and an Absorbable Collagen Sponge: A Prospective Pilot Clinical Study.

PURPOSE: The aim of this study was to clinically, radiologically, and histologically evaluate a sinus augmentation technique using a resorbable collagen sponge to maintain space between the Schneiderian membrane and the residual crestal bone. MATERIALS AND METHODS: Patients with partially edentulous maxillae were clinically and radiographically evaluated for implant placement. A total of 10 consecutive patients with the bone height for implant placement (<4.0 mm) were enrolled in the study. The lateral maxillary wall was surgically exposed and the Schneiderian membrane was carefully elevated. A collagen wound dressing was placed in the antral area between the sinus floor and the raised membrane. The vertical sinus floor height was calculated using cone-beam computed tomography before the surgical procedure (baseline) and at 6 months postoperative. Immediately after the second scan, a core biopsy was removed for histological evaluation. The biopsy site was then further prepared for implant placement in the same location. RESULTS: Biopsies showed mature cancellous bone with a predominantly lamellar structure. Well-vascularized intertrabecular spaces were filled with connective tissue and bone marrow. Analysis of bone height changes showed significant mean (SD) differences before and after procedures in anterior (2.67 ± 0.62 mm and 11.15 ± 1.1 mm), medial (2.98 ± 0.55 mm and 10.96 ± 0.77 mm), and posterior (3.17 ± 0.91 mm and 10.63 ± 0.51 mm) maxillary jaw locations (P = 0.005). CONCLUSION: The collagen sponge provided an effective substrate for osseous regeneration of the sinus floor.