National Science Foundation     |     Directorate for Engineering  (ENG)
Division of Chemical, Bioengineering, Environmental, & Transport Systems  (CBET)
CBET Award Achievements 
Notable Accomplishments from CBET Awards
Novel Methods for Growing Stable Stem Cells
Raj Rao  -  Virginia Commonwealth University

Simplified Description

Outcome or Accomplishment:  Raj Rao and members of his research group at Virginia Commonwealth University (VCU) have developed a new material for growing stable, non-tumor forming stem cells in culture without the use of animal products.

Impact:  Current methods for growing stem cells use animal components that can carry disease and are relatively inefficient.  These methods also result in cells that are unstable and carry mutations and are capable of causing tumors.  The materials Rao and his team have developed can be used to multiply stem cells in an environment that is free of animal products, and that results in stem cells that are stable and therefore unlikely to form tumors.  Ultimately, stable and non-tumor forming, disease free stem cells will be essential so that stem cells can safely be used to treat human diseases.

Background the lay reader needs to understand the significance of this outcome:  Human stem cells have gained enormous interest as potential sources for regenerative biomedical therapies and model systems for studying early human development.  Traditionally, growing human stem cells have involved use of animal-derived components in culture conditions.  The use of these animal derived components presents concerns about the possibility of contamination and spread of disease, labor intensiveness and variability in experimental results in human stem cell cultures.  In addition, traditional culture systems lead to a mixture of stem cells, some which develop into normal tissues and cells, and others that form cancers.  Stem cell cancers are typically some of the hardest to treat.  Rao's findings will enable investigators to use well defined materials that can be used to manufacture safe stem cells, that are disease free and will result in stable, non-tumor forming stem cells.  Such safe stem cells are essential if stem cell therapies are to be used for the treatment of human diseases can be produced.

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Detailed Engineering Description

Background:  Stem cells have tremendous potential to be used in regenerative medicine and tissue engineering applications, either to repair or replace damaged tissues or organs.  Some of the biggest challenges facing the development of stem cell therapies and stem cell engineering is the heterogeneity of most stem cell populations, making control of differentiation challenging, the use of animal products in traditional culture methods, increasing the risk of disease transfer from animals to humans, and the potential of stem cells to become unstable and develop into cancers.  Stem cells require specific cues in their microenvironment that promote their survival and growth and influence their stability and differentiation potential.  Raj Rao and members of his research group at Virginia Commonwealth University have developed novel methods that promote growth of stable (non cancer forming) stem cells in culture.  The methods developed as part of this study will provide researchers an opportunity to elucidate the components of substrates that can promote growth of stem cells for use in regenerative medicine.

Results: Rao and his group have developed novel methodologies to engineer substrates that promote growth of stem cells in culture.  Using proteomic approaches, they have focused on identifying and characterizing components of the microenvironment that are essential for growing stem cells.  Studies have identified core components of extracellular matrix (ECM)-derived substrates that can promote adhesion and activation of intracellular pathways responsible for stable stem cell growth.  Researchers have demonstrated that multiple stem cell lines could be maintained on these substrates and exhibited key features of stemness.
Expansion of stem cells will require a better understanding of biochemical and biophysical cues of the microenvironment surrounding the stem cells.  Thorough characterization of extracellular matrix (ECM)-derived substrates will greatly contribute to generation of defined engineered substrates crucial for stem cell growth, prior to use in regenerative biomedical therapies.

- 1 -  Abraham, S; Eroshenko, N; Rao, RR. "Role of bioinspired polymers in determination of pluripotent stem cell fate," REGENERATIVE MEDICINE, v.4, 2009, p. 561-578.
- 2 -  Abraham, S; Riggs, MJ; Nelson, K; Lee, V; Rao, RR. "Characterization of human fibroblast-derived extracellular matrix components for human pluripotent stem cell propagation," ACTA BIOMATERIALIA, v.6, 2010, p. 4622-4633.
- 3 -  Abraham, S; Sheridan, SD; Laurent, LC; Albert, K; Stubban, C; Ulitsky, I; Miller, B; Loring, JF; Rao, RR. "Propagation of human embryonic and induced pluripotent stem cells in an indirect co-culture system," BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, v.393, 2010, p. 211-216.
- 4 -  Abraham, S; Sheridan, SD; Miller, B; Rao, RR. "Stable Propagation of Human Embryonic and Induced Pluripotent Stem Cells on Decellularized Human Substrates," BIOTECHNOLOGY PROGRESS, v.26, 2010, p. 1126-1134.

Raj Rao Image   Figure 1.  Human stem cells on defined substrates
Image Credit:  Raj Rao, Virginia Commonwealth University
Scientific Uniqueness:  The research team has developed novel methods that will lead to defined, well characterized microenvironments for growing stable stem cells.

This project addresses the NSF Strategic Outcome Goals, as described in the NSF Strategic Plan 2006-2011, as follows:
- 1 Primary Strategic Outcome Goal:      (1) Discovery:  This research has led to development of new methods based on well-characterized substrates for growing stem cells.  In addition, the research has identified components of matrices that can provide multiple cues to grow stable stem cells for regenerative biomedical applications.
- 2 Secondary Strategic Outcome Goal:  (2) Learning:  Over the course of this project, three graduate students and two undergraduate students have been involved in this research and received training in many aspects of stem cell culture, characterization of stem cells under different experimental conditions and molecular approaches to analyze data obtained from stem cells.  In addition, Rao has been active in educating high school students and the general public in the Greater Richmond community.

This Award Achievement represents potentially Transformative Research:  The discoveries and methodologies developed as part of this project have the potential to be transformative based on engineering substrates that not only support the growth of stem cells but also preserve their stability in long term culture.  These methods will enable development of new products that can be used to eliminate tumor causing stem cells from normal stem cells, thus enabling safer stem cell therapies.

The Intellectual Merit of this project is the development of an integrated system for growing stable human stem cells in culture.  The propagation system developed as part of this project will meet specific expectations that aim to:
(i)  be efficient, producing high densities and quantities stem cells;
(ii)  maintain stem cells genotypic and phenotypic integrity over several generations, thus reducing cancer potential; and finally,
(iii)  use only defined, animal-product free culture components.
This work is notable because the research addresses fundamental mechanical issues affecting an important health concern.  It has advanced intellectual understanding of cell-scale transport in blood, and it does this by using advanced methods to harness the huge advances that have been made in computational resource infrastructure.

The Broader Impacts of this activity include:
- 1Benefits to society:  Results from this research will directly impact the emerging field of cell-based regenerative medicine, providing enabling technologies for growing stable stem cells.
- 2Broadening participation of underrepresented groups:  Rao is active in engaging underrepresented minorities in his research program.  Rao has trained female minority undergraduate students funded through the VCU Initiative for Maximizing Student Diversity (IMSD) scholars; the Health Educational Research Opportunities (HERO) program; and the Short-term Educator Program for Underrepresented Persons (STEP-UP) research programs.  He has also engaged high school students participating in the Richmond Area Program for Minorities in Engineering (RAPME) program.
- 3Advancing discovery and understanding while promoting teaching, training, and learning:  Three graduate students and two undergraduate students have directly participated in the research described.  In addition, Rao has incorporated results from research into undergraduate and graduate courses, and in stem cell training workshops.  Rao also produced a video on stem cells to be used in educating middle and high school students in the Richmond community.
- 4Results disseminated broadly to enhance scientific and technological understanding:  Rao will continue to publish results generated from this work in high impact journals and present at national and international meetings.

Program Director:
Theresa Good
CBET Program Director - Biotechnology, Biochemical, and Biomass Engineering
NSF Award Number:   0744556
Award Title:   CAREER: Propagation systems for generation of chromosomally stable human embryonic stem cells
PI Name:   Raj Rao
Institution Name:   Virginia Commonwealth University
Program Element Code:   1491
CBET Award Achievement:

  FY 2011

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This Award Achievement was Updated on 17 March 2011.