A concept for scaffold-based tissue engineering in alveolar cleft osteoplasty.

Background: Alveolar cleft osteoplasty (ACO) using autologous bone grafts, is used worldwide as a standard treatment in the management of patients with clefts. Harvesting of the various autologous bone grafts is accompanied by considerable donor-site morbidity. Use of scaffold-based tissue engineering in ACO could potentially provide treatment options with decreased, or no donor-site morbidity. This study aims to demonstrate the technical and cell biological feasibility of using scaffold-based tissue engineering in ACO.

Material And Methods: Pre-existing cone-beam computed tomography scans were used for 3D printing of custom-made scaffolds (tricalcium phosphate-polyhydroxybutyrate (TCP-PHB)) according to the individual geometry of the alveolar bone in patients with clefts. The scaffolds were seeded with commercially available human mesenchymal stem cells (hMSCs). Cell survival and cell proliferation was monitored by live-dead assay, scanning electron microscopy (SEM) and WST-1 assay. The osteogenic differentiation of hMSCs on the scaffolds was evaluated by alkaline phosphatase (ALP) assay.

Results: The custom-made scaffolds were nearly identical to the size and shape of the digital master. Approximately 91% of the subsequently applied mesenchymal stem cells could be seeded on the rails. We could demonstrate successful cell proliferation by a factor of 5-7 over the first 3 weeks. SEM showed a pore-border growth of the hMSCs on the scaffolds after 3 weeks of cell proliferation. The successful osteogenic differentiation of the scaffold-seeded cells could be demonstrated.

Conclusion: The concept of scaffold-based tissue engineering provides great potential as an alternative for the present gold standard of autologous bone grafts in ACO. The treatment causes less morbidity and is less invasive for managing young patients with cleft alveolar bone defects. Further in vivo studies and clinical trials are needed to demonstrate the advantages of this novel treatment for ACO in the clinical setting.