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5. TUBULAR PERFUSION SYSTEM BIOREACTOR FOR THE DYNAMIC CULTURE OF HUMAN MESENCHYMAL STEM CELLS

Author

Yeatts, Andrew Bryan and Yeatts, Andrew Bryan

Abstract

In vitro culture techniques must be improved in order to increase the feasibility of cell based tissue engineering strategies. Limitations of current techniques are largely a result of the slow diffusion of molecules such as oxygen into the interior of three dimensional scaffolds in static culture. In order to enhance nutrient transport we have developed a novel bioreactor, the tubular perfusion system (TPS), to culture human mesenchymal stem cells (hMSCs) in three dimensional scaffolds. In our design, hMSCs are cultured on scaffolds tightly packed in a tubular growth chamber. Media is perfused by a peristaltic pump through the growth chamber and around the tightly packed scaffolds. In the first part of the work hMSCs are encapsulated in alginate scaffolds and results demonstrate bioreactor culture enhances late osteoblastic differentiation of hMSCs. An investigation into shear stress in the system revealed that osteogenic markers increase with increasing shear stress and that the differentiation of hMSCs is dependent on cell radial position within scaffolds. In order to enhance the ability to implant these constructs in vivo, a method to create an aggregated cell containing construct in vitro in a bioreactor system was developed. In this part of the work hMSCs are cultured in individual alginate beads in the TPS bioreactor and the beads are aggregated to form one large construct. Following this the TPS bioreactor was investigated to culture synthetic poly-L-lactic acid scaffolds which were fabricated using supercritical carbon dioxide gel drying. In addition to investigating the effects of perfusion on hMSC growth in these scaffolds, the effect of microporosity was investigated. In the final part of the work, a study was completed to determine how TPS culture influenced in vivo bone regeneration. Here alginate beads as well as synthetic PLGA/PCL constructs were used as scaffolds. Results revealed the efficacy of using the tubular perfusion system for bone tissue en

Published
2012

16. Meta-Analysis of Microarray Studies Reveals a Novel Hematopoietic Progenitor Cell Signature and Demonstrates Feasibility of Inter-Platform Data Integration

Author

Sohal, Davendra, primary, Yeatts, Andrew, additional, Ye, Kenny, additional, Pellagatti, Andrea, additional, Zhou, Li, additional, Pahanish, Perry, additional, Mo, Yongkai, additional, Bhagat, Tushar, additional, Mariadason, John, additional, Boultwood, Jacqueline, additional, Melnick, Ari, additional, Greally, John, additional, and Verma, Amit, additional

Published
2008
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18. A High Resolution Epigenomic Map of Myelofibrosis Reveals Multiple Chromosomal Deletions and Amplifications Accompanied by a High Level of Functionally Important Methylation.

Author

Opalinska, Joanna, primary, Sohal, Davendra, additional, Parmar, Simrit, additional, Zhou, Li, additional, Yeatts, Andrew, additional, Pahanish, Perry, additional, Isulfi, Iris, additional, Ye, Kenny, additional, Figueroa, Maria, additional, Melnick, Ari, additional, Greally, John, additional, and Verma, Amit, additional

Published
2006
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19. In VivoBone Regeneration Using Tubular Perfusion System Bioreactor Cultured Nanofibrous Scaffolds

Author

Yeatts, Andrew B., Both, Sanne K., Yang, Wanxun, Alghamdi, Hamdan S., Yang, Fang, Fisher, John P., and Jansen, John A.

Abstract

The use of bioreactors for the in vitroculture of constructs for bone tissue engineering has become prevalent as these systems may improve the growth and differentiation of a cultured cell population. Here we utilize a tubular perfusion system (TPS) bioreactor for the in vitroculture of human mesenchymal stem cells (hMSCs) and implant the cultured constructs into rat femoral condyle defects. Using nanofibrous electrospun poly(lactic-co-glycolic acid)/poly(ɛ-caprolactone) scaffolds, hMSCs were cultured for 10 days in vitroin the TPS bioreactor with cellular and acellular scaffolds cultured statically for 10 days as a control. After 3 and 6 weeks of in vivoculture, explants were removed and subjected to histomorphometric analysis. Results indicated more rapid bone regeneration in defects implanted with bioreactor cultured scaffolds with a new bone area of 1.23±0.35 mm2at 21 days compared to 0.99±0.43 mm2and 0.50±0.29 mm2in defects implanted with statically cultured scaffolds and acellular scaffolds, respectively. At the 21 day timepoint, statistical differences (p<0.05) were only observed between defects implanted with cell containing scaffolds and the acellular control. After 42 days, however, defects implanted with TPS cultured scaffolds had the greatest new bone area with 1.72±0.40 mm2. Defects implanted with statically cultured and acellular scaffolds had a new bone area of 1.26±0.43 mm2and 1.19±0.33 mm2, respectively. The increase in bone growth observed in defects implanted with TPS cultured scaffolds was statistically significant (p<0.05) when compared to both the static and acellular groups at this timepoint. This study demonstrates the efficacy of the TPS bioreactor to improve bone tissue regeneration and highlights the benefits of utilizing perfusion bioreactor systems to culture MSCs for bone tissue engineering.

Published
2014
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21. Nondestructive imaging of stem cell in 3D scaffold

Author

Chen, Chao-Wei, Yeatts, Andrew B., Fisher, John P., and Chen, Yu

Abstract

We have developed a line-scanning angled fluorescent laminar optical tomography (LS-aFLOT) system. This system enables three-dimensional imaging of fluorescent-labeled stem cell distribution within engineered tissue scaffold over a several-millimeter field-of-view.

Published
2012
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