Development of functional reconstructive surgery in cranio-maxillo-facial area using tissue engineering

点击翻译按钮获取中文摘要

We demonstrated the hollow structure of regenerated cartilage in polymer scaffolds and speculated that immature structure was related to blockage of inflow of nutrients through polymer structure and hard neo-cartilage. In other words, oxygen and nutrients are critical for surviving and maintaining of seeded cells inside the deep layer of the polymer scaffold. To solve this problem, we investigated a biodegradable natural polymer compared to conventional synthetic biodegradable polymers. A sheet of the natural polymer showed significantly better permeability of oxygen and nutrients than a sheet of conventional polymer. To create three-dimensional shapes, organic solvent was used to cast specific shaped sucrose particles. However, since organic solvent was not safe enough even after complete evaporation for clinical applications, we have developed a new procedure using salt and water. Sponge structure was maintained and cartilaginous matrix was regenerated not only near the surface area, but also in the deep center of scaffolds. However, in vitro cartilage regeneration required long term culture at least few months.We faced many difficulties on proliferation and differentiation of bone marrow derived stromal cells (BMSC). BMSC required maintaining high cell density even after primary culture for proliferation. Unless high cell density was kept, cellular morphology became flat and wide. That means BMSC were differentiated and stopped proliferating. Other studies showed that more and more time and growth factors were required for cartilaginous regeneration in order of BMSC, progenitor cells in cartilage membrane and chondrocytes inside cartilage. Therefore we should consider economical condition for clinical application of BMSC using in vitro regeneration procedures.