23 research outputs found
Development of multiwave-based bioprinting technology
Pluripotent stem cells (PSCs) are the most favourable sources of cells for tissue engineering applications due to their unique potency and self-renewal characteristics however they are quite fragile and can be directed to differentiate erroneously by the application of external forces. A novel multi-nozzle valve-based bioprinting platform was developed that was able to position droplets of bio-ink – such as cells in suspension – with high spatial accuracy and low impact. Volumes as low as 2 nL were successfully dispensed. Several different versions of the machine were created before the final machine was made integrating improvements and solutions to problems encountered during development. A complete evaluation of cell compatibility was carried out in order to quantify the response of cells to the bioprinting process. In the first ever study of this kind, the viability and pluripotency of human embryonic and induced pluripotent stem cells was investigated post-printing and were found to be almost completely unaffected by the bioprinting process. Many cells require a 3D culture environment in order to maintain their in vivo functions. A hybrid bioprinted-hanging-droplet technique was used to create uniform spheroid aggregates of programmable sizes from PSCs which could be used to direct PSC differentiation or as building blocks for tissue generation. Hydrogels can also be used to recreate the 3D in vivo cellular environment using the bioprinter. Alginate and hybrid polypeptide-DNA hydrogels were used, the latter for the first time with a bioprinting platform. Complex 3D structures could be created in a layer-by-layer approach with programmable heterogeneous properties throughout. Cells were added to the hydrogel precursor solution and used to bioprint 3D structures. The cells were found to be functional and highly viable while being encapsulated throughout the 3D structure of the bioprinted hydrogel which will allow the future creation of more accurate human tissue models. PSCs were successfully directed to differentiate into hepatocyte-like cells. It was shown that the bioprinting process did not interrupt or alter the pre-programmed differentiation of the cells which means that these cells can be patterned in 3D using the bioprinter while differentiating, greatly speeding up the creation of mini-liver tissue. Hepatic stellates and HUVECs were co-cultured with the hepatocyte-like cells in various ratios in an attempt to improve their hepatic function. However, no clear improvement in cytochrome P450 activity was observed indicating that further optimisation is required in this area
Development of multivalve-based bioprinting technology
Pluripotent stem cells (PSCs) are the most favourable sources of cells for tissue engineering applications due to their unique potency and self-renewal characteristics however they are quite fragile and can be directed to differentiate erroneously by the application of external forces. A novel multi-nozzle valve-based bioprinting platform was developed that was able to position droplets of bio-ink – such as cells in suspension – with high spatial accuracy and low impact. Volumes as low as 2 nL were successfully dispensed. Several different versions of the machine were created before the final machine was made integrating improvements and solutions to problems encountered during development. A complete evaluation of cell compatibility was carried out in order to quantify the response of cells to the bioprinting process. In the first ever study of this kind, the viability and pluripotency of human embryonic and induced pluripotent stem cells was investigated post-printing and were found to be almost completely unaffected by the bioprinting process. Many cells require a 3D culture environment in order to maintain their in vivo functions. A hybrid bioprinted-hanging-droplet technique was used to create uniform spheroid aggregates of programmable sizes from PSCs which could be used to direct PSC differentiation or as building blocks for tissue generation. Hydrogels can also be used to recreate the 3D in vivo cellular environment using the bioprinter. Alginate and hybrid polypeptide-DNA hydrogels were used, the latter for the first time with a bioprinting platform. Complex 3D structures could be created in a layer-by-layer approach with programmable heterogeneous properties throughout. Cells were added to the hydrogel precursor solution and used to bioprint 3D structures. The cells were found to be functional and highly viable while being encapsulated throughout the 3D structure of the bioprinted hydrogel which will allow the future creation of more accurate human tissue models. PSCs were successfully directed to differentiate into hepatocyte-like cells. It was shown that the bioprinting process did not interrupt or alter the pre-programmed differentiation of the cells which means that these cells can be patterned in 3D using the bioprinter while differentiating, greatly speeding up the creation of mini-liver tissue. Hepatic stellates and HUVECs were co-cultured with the hepatocyte-like cells in various ratios in an attempt to improve their hepatic function. However, no clear improvement in cytochrome P450 activity was observed indicating that further optimisation is required in this area
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Laboratory Directed Research and Development Program FY 2005 Annual Report
The Oak Ridge National Laboratory (ORNL) Laboratory Directed Research and Development (LDRD) Program reports its status to the U.S. Department of Energy (DOE) in March of each year. The program operates under the authority of DOE Order 413.2A, 'Laboratory Directed Research and Development' (January 8, 2001), which establishes DOE's requirements for the program while providing the Laboratory Director broad flexibility for program implementation. LDRD funds are obtained through a charge to all Laboratory programs. This report describes all ORNL LDRD research activities supported during FY 2005 and includes final reports for completed projects and shorter progress reports for projects that were active, but not completed, during this period. The FY 2005 ORNL LDRD Self-Assessment (ORNL/PPA-2006/2) provides financial data about the FY 2005 projects and an internal evaluation of the program's management process. ORNL is a DOE multiprogram science, technology, and energy laboratory with distinctive capabilities in materials science and engineering, neutron science and technology, energy production and end-use technologies, biological and environmental science, and scientific computing. With these capabilities ORNL conducts basic and applied research and development (R&D) to support DOE's overarching national security mission, which encompasses science, energy resources, environmental quality, and national nuclear security. As a national resource, the Laboratory also applies its capabilities and skills to the specific needs of other federal agencies and customers through the DOE Work For Others (WFO) program. Information about the Laboratory and its programs is available on the Internet at <http://www. ornl.gov/>. LDRD is a relatively small but vital DOE program that allows ORNL, as well as other multiprogram DOE laboratories, to select a limited number of R&D projects for the purpose of: (1) maintaining the scientific and technical vitality of the Laboratory; (2) enhancing the Laboratory's ability to address future DOE missions; (3) fostering creativity and stimulating exploration of forefront science and technology; (4) serving as a proving ground for new research; and (5) supporting high-risk, potentially high-value R&D. Through LDRD the Laboratory is able to improve its distinctive capabilities and enhance its ability to conduct cutting-edge R&D for its DOE and WFO sponsors. To meet the LDRD objectives and fulfill the particular needs of the Laboratory, ORNL has established a program with two components: the Director's R&D Fund and the Seed Money Fund. As outlined in Table 1, these two funds are complementary. The Director's R&D Fund develops new capabilities in support of the Laboratory initiatives, while the Seed Money Fund is open to all innovative ideas that have the potential for enhancing the Laboratory's core scientific and technical competencies. Provision for multiple routes of access to ORNL LDRD funds maximizes the likelihood that novel and seminal ideas with scientific and technological merit will be recognized and supported