Effect of interferon-alpha-2b on porcine mesenchymal stem cells.

PURPOSE: Patients undergoing enucleation and adjuvant interferon therapy for giant cell jaw tumors have been observed to exhibit exuberant bone formation in the resultant defects. We hypothesize that interferon promotes bone formation by enhancing mesenchymal stem cell (MSC) differentiation and by stimulating osteoblasts. This is a preliminary study to determine the effects of interferon on porcine mesenchymal stem cells (pMSCs) in culture. MATERIALS AND METHODS: Isolated pMSCs were grown under the following conditions: 1) MSCs alone (negative control); 2) MSCs + osteogenic supplements (positive control); and 3) MSCs + interferon (experimental). Cell cultures were evaluated morphologically, by quantitative DNA analysis, and quantitative and qualitative alkaline phosphatase analysis. RESULTS: Cells treated with interferon exhibited a slower but constant proliferation rate, did not clump, and produced more alkaline phosphatase as compared with the negative control. CONCLUSION: The data indicate that interferon may act to differentiate MSCs into osteoblasts and to stimulate metabolic activity while not increasing the proliferation rate.

The engineering of craniofacial tissues in the laboratory: a review of biomaterials for scaffolds and implant coatings.

Tissue engineering is a rapidly growing interdisciplinary field that focuses on the interactions between cells, growth factors, and scaffolds to produce replacement tissue and organs. Recent developments in tissue engineering technology include refinements in isolation and differentiation of progenitor cells, 3-D printing technology to produce scaffolds, new biomaterials for scaffolds, and growth factor delivery systems. The purpose of this article is to review advances in biomaterials, scaffolds, and implant coatings for craniomaxillofacial (bone) tissue engineering.

Reconstruction of mandibular defects with autologous tissue-engineered bone.

PURPOSE: Maxillofacial reconstructive procedures often require bone graft harvesting, which results in donor site morbidity; the use of tissue-engineered bone would eliminate this problem. In this study, a novel scaffold design and new fabrication protocol were used to produce autologous tissue-engineered constructs (scaffolds seeded with cells) to reconstruct segmental mandibular defects in a minipig model. MATERIALS AND METHODS: Porcine mesenchymal stem cells were isolated from the ilium. They were expanded in culture and seeded onto poly-dl-lactic-coglycolic acid scaffolds. The constructs were placed in a bioreactor and incubated for 10 days in medium and osteogenic supplements. Four full-thickness bony defects (2 x 2 cm) were created in the same pig's mandible. The constructs (n = 2) were placed into 2 of the defects as autologous grafts. One unseeded scaffold and 1 empty defect served as controls. At 6 weeks postimplantation, the pig was sacrificed, the mandible was harvested, and the grafted sites were evaluated by clinical, radiographic, and histologic methods. RESULTS: The construct-implanted defects appeared to be filled with hard tissue resembling bone, whereas controls were filled with fibrous tissue. Radiographically, the tissue-engineered constructs were uniformly radiodense with bone distributed throughout. The interface between native bone and constructs was indistinct. Complete bone ingrowth was not observed in control defects. Osteoblasts, osteocytes, bone trabeculae, and blood vessels were identified throughout the defects implanted with constructs. CONCLUSION: This "proof-of-principle" study indicates that porcine mandibular defects can be successfully reconstructed by in vitro cultured autologous porcine mesenchymal stem cells on a biodegradable polymer scaffold with penetration of bone and blood vessels.