Osteogenic differentiation of bone marrow derived stem cells in gelatin-hydroxyapatite nanocomposite

PURPOSE: Gelatin-hydroxyapatite nanocomposite is similar to inorganic nanostructure of bone. To make a scaffold with osteoinductivity, bone marrow derived stem cells from rabbit femur were impinged into the nanocomposite. This vitro study was to test osteogenic differentiation of the stem cells in the nanocomposite, which was made by authors. MATERIAL & METHODS: Gel-HA nanocomposite with 10g of HA, 3 g of Gel has been made by co-precipitation process. Bone marrow was obtained from femur of New Zealand White rabbits and osteogenic differentiation was induced by culturing of the BMSCs in an osteogenic medium. The BMSCs were seeded into the Gel-HA nanocomposite scaffold using a stirring seeding method. The scaffolds with the cells were examined by scanning electron microscopy (SEM), colorimetry assay, biochemical assay with alkaline phosphatase (ALP) diagnostic kit, osteocalcin ELISA kit. RESULTS: Gel-HA nanocomposite scaffolds were fabricated with relatively homogenous microscale pores (20-40 micrometer). The BMSCs were obtained from bone marrow of rabbit femurs and confirmed with flow cytometry, Alizarin red staining. Attachment and proliferation of BMSCs in Gel-HA nanocomposite scaffold could be identified by SEM, ALP activity and osteocalcin content of BMSCs. CONCLUSION: The Gel-HA nanocomposite scaffold with micropores could be fabricated and could support BMSCs seeding, osteogenic differentiation.

Osteogenic differentiation of bone marrow derived stem cells in gelatin-hydroxyapatite nanocomposite

PURPOSE: Gelatin-hydroxyapatite nanocomposite is similar to inorganic nanostructure of bone. To make a scaffold with osteoinductivity, bone marrow derived stem cells from rabbit femur were impinged into the nanocomposite. This vitro study was to test osteogenic differentiation of the stem cells in the nanocomposite, which was made by authors. MATERIAL & METHODS: Gel-HA nanocomposite with 10g of HA, 3 g of Gel has been made by co-precipitation process. Bone marrow was obtained from femur of New Zealand White rabbits and osteogenic differentiation was induced by culturing of the BMSCs in an osteogenic medium. The BMSCs were seeded into the Gel-HA nanocomposite scaffold using a stirring seeding method. The scaffolds with the cells were examined by scanning electron microscopy (SEM), colorimetry assay, biochemical assay with alkaline phosphatase (ALP) diagnostic kit, osteocalcin ELISA kit. RESULTS: Gel-HA nanocomposite scaffolds were fabricated with relatively homogenous microscale pores (20-40 micrometer). The BMSCs were obtained from bone marrow of rabbit femurs and confirmed with flow cytometry, Alizarin red staining. Attachment and proliferation of BMSCs in Gel-HA nanocomposite scaffold could be identified by SEM, ALP activity and osteocalcin content of BMSCs. CONCLUSION: The Gel-HA nanocomposite scaffold with micropores could be fabricated and could support BMSCs seeding, osteogenic differentiation.

Clinicopathologic Features of Poorly Differentiated (Insular) Carcinoma of Thyroid

PURPOSE: Well-differentiated carcinomas of the thyroid run an excellent clinical course. However 10~20% of thyroid carcinomas showed poor clinical outcomes. Insular carcinomas are an uncommon thyroglobulin-producing neoplasm, which show intermediate prognosis between well-differentiated carcinomas and undifferentiated anaplastic carcinomas, and their clinicopathologic features are poorly understood. Therefore, we aimed to investigate the clinicopathologic features and the prognosis of insular thyroid carcinomas. METHODS: We reviewed 10 patients who underwent an operation due to an insular thyroid carcinoma at Seoul National University Hospital between January 1990 and December 2001. Their clinicopathologic features and follow-up findings were retrospectively reviewed and compared. RESULTS: Four male and six female patients are reviewed, with a mean age of 54.8+/-6.4187, ranging from 37 to 69 years. Pathologically, eight of the tumors consisted of pure insular carcinoma and the others showed a papillary carcinoma as the major component and a minor insular component. The mean tumor size was 4.53 cm (4.53+/-1.4288 cm). An extrathyroidal extension was present in 7 cases and a vascular invasion in 6. Distant metastasis and local relapse of the regional lymph node were seen in 9 patients. Comparing the survivor and expired groups, all the male patients were in the expired group, and the mean tumor size was larger in the expired group (5.46 cm vs. 3.6 cm). But these differences were not statistically significant. CONCLUSION: Our study revealed that insular carcinomas have distinctive clinicopathologic features, and recognition of this histologic variant is important and significant for management of these unique tumors.