Amniotic membrane and adipose-derived stem cell co-culture system enhances bone regeneration in a rat periodontal defect model.

BACKGROUND/PURPOSE: Periodontal disease is a chronic inflammatory process that potentially leads to alveolar bone destruction and tooth loss. Tissue engineering combined with stem cell therapy is a potential effective treatment for periodontal bone loss. Amniotic membrane (AM) is a potential scaffold enriched with multiple growth factors. It has the effects of anti-inflammation, antiangiogenesis, and immunosuppression. Herein, we used adipose-derived stem cells (ADSCs) and an AM co-cultured system to study bone regeneration in a rat periodontal defect model in vivo. METHODS: Human ADSCs were isolated from the infrapatellar fat pad, and characterized by flow cytometry, reverse transcription-polymerase chain reaction, and multipotent differentiation assays. The co-culture system was applied in the periodontal two-wall osseous defect in a rat model, and computed tomography was used to measure the effect. RESULTS: Human ADSCs isolated from the infrapatellar fat pad showed spindle-like morphology. Flow cytometry results demonstrated that ADSCs expressed a high level of CD90 and CD105, but not CD31, CD34, and CD45. ADSCs strongly expressed stemness genes, including SOX2, OCT4, NANOG, and KLF4 on different passages. Furthermore, ADSCs were able to differentiate into osteogenic, chondrogenic, and adipogenic cells. In the periodontal osseous defect rat model, ADSCs and the AM co-culture system significantly increased bone regeneration. CONCLUSION: This study provides the basis for using ADSCs with an AM co-culture system as stem cell therapy and scaffold transplantation in clinical periodontology.

Application of the surface free energy minimization principle to modify the indentation of a polymer mirror structure.

This paper successfully used inclined exposure technology to fabricate 45 degrees polymer optical grade micromirrors (approximately 1.4 mm thick) while applying the surface free energy minimization principle to improve sidewall indentation. This paper tests the effect of the reflow process on the surface roughness of inclined surfaces. Experimental results are considered in light of the theory of minimizing free energy. The smallest surface roughness achieved in the experiments using SU-8 material with a thickness of 1.4 mm was less than 20 nm. The effect of the reflow process on the surface indentation of inclined microstructures showed that the 1D WYKO profile of maximum height fell from 0.81 microm to 0.08 microm (R(t)), which is an improvement of 90% after the reflow process. This type of micromirror can be used as a key component in Blu-Ray optical pickup heads used in portable, high-density storage systems.