tailieunhanh - báo cáo khoa học: " Embryonic stem cells in scaffold-free threedimensional cell culture: osteogenic differentiation and bone generation"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Embryonic stem cells in scaffold-free threedimensional cell culture: osteogenic differentiation and bone generation | Handschel et al. Head Face Medicine 2011 7 12 http content 7 1 12 HEAD FACE MEDICINE RESEARCH Open Access Embryonic stem cells in scaffold-free threedimensional cell culture osteogenic differentiation and bone generation 1 1 1 2 1 1 Jorg Handschel Christian Naujoks Rita Depprich Lydia Lammers Norbert Kubler Ulrich Meyer and Hans-Peter Wiesmann3 Abstract Extracorporeal formation of mineralized bone-like tissue is still an unsolved challenge in tissue engineering. Embryonic stem cells may open up new therapeutic options for the future and should be an interesting model for the analysis of fetal organogenesis. Here we describe a technique for culturing embryonic stem cells ESCs in the absence of artificial scaffolds which generated mineralized miromasses. Embryonic stem cells were harvested and osteogenic differentiation was stimulated by the addition of dexamethasone ascorbic acid and R-glycerolphosphate DAG . After three days of cultivation microspheres were formed. These spherical threedimensional cell units showed a peripheral zone consisting of densely packed cell layers surrounded by minerals that were embedded in the extracellular matrix. Alizarine red staining confirmed evidence of mineralization after 10 days of DAG stimulation in the stimulated but not in the control group. Transmission electron microscopy demonstrated scorching crystallites and collagenous fibrils as early indication of bone formation. These extracellular structures resembled hydroxyl apatite-like crystals as demonstrated by distinct diffraction patterns using electron diffraction analysis. The micromass culture technique is an appropriate model to form three-dimensional bone-like micro-units without the need for an underlying scaffold. Further studies will have to show whether the technique is applicable also to pluripotent stem cells of different origin. Keywords Embryonal stem cell osteogenic tissue engineering three-dimensional culture technique scaffold free .