Cytotherapeutic Cell Manufacture at Texas A&M University
Key Personnel: Andrew Haskell
Mesenchymal stem cells (MSCs) are a promising therapeutic for bone regeneration following traumatic bone injury and several bone cancers but current methods of producing MSCs is too expensive and time consuming to be used in a clinical setting. In collaboration with other groups at the Institute for Regenerative Medicine, Biomedical Engineering, and the National Center for Therapeutics Manufacturing (all located at Texas A&M University), this project is focused on the development of technologies to allow for cost-effective, large-scale manufacturing of MSCs for clinical use. We aim to accomplish this goal in three ways:
- MSCs are grown while attached to gelatin-methacrylarloyl (GelMA) spheres that are approximately 100 microns in diameter. This not only increases the surface area available for cell growth but will allow us to reduce the concentration of expensive reagents and potentially provide a means of replacing these reagents with cheaper alternatives.
- Cell growth will be continuously monitored by a computer program that will be able to determine the viability of the cell culture based on morphology. This will reduce the workload on technicians and will standardize morphologic analysis by eliminating errors caused by inconsistent human interpretation. The program will also be able to control the concentration of bioactive factors in the growth medium based on culture health, minimizing the cost to manufacture the cells.
- Cells on GelMA microcarriers will be grown in large bioreactors. This will allow for the manufacture of MSCs to be scaled based on space and budgetary limitations of the facility without the need for cumbersome incubators to store small plates. Based on our recent experiments, we estimate that using these large bioreactors with our microcarriers will reduce manufacturing costs by thousands of dollars per patient dose of MSC-based therapies.
DKK-1 in Osteosarcoma: targeting dual mechanisms
Key Personnel: Simin Pan
Malignant bone disease (MBD) is characterized in part by osteolytic lesions (OLs), defined as tumor-filled holes in bone tissue [Fig1]. OLs frequently fail to heal, even with interventions, providing an effective niche for tumor repopulation. OLs also cause untreatable pain and fracture.
It is known that tumors secrete Wnt inhibitors (WIs), which have the capacity to inhibit canonical Wnt (cWnt) signaling, a key pathway that drives the differentiation of bone marrow mesenchymal stem cells (MSCs) to bone-synthesizing osteoblasts.
Several types of WI are involved in OL formation, but Dickkopf-1 (Dkk-1) is the most common, associated with multiple myeloma (MM), osteosarcoma (OS), and breast and prostate metastases.
High serum DKK1 gynecological cancer, multiple myeloma, Hepatocellular Carcinoma, breast cancer are also related to poor prognosis in patient.
Our goal is to modulate the activity of WIs (most notable Dkk-1) to prevent or repair OLs and possibly inhibit disease progression.
MSC Culture in 3D-Printed Perfusion Bioreactors
Key Personnel: Andrew Haskell (Inactive)
While microcarrier-mediated bioreactor culture is a promising option for culturing adherent cells, some cell lines may not be compatible with microcarrier culture due to the shear stress and other challenges presented by the motion of microcarriers in bioreactors. Our collaborators at Southwest Research Institute (SwRI) have created a 3D-printed perfusion bioreactor that consists of several channels, maximizing the growth area for monolayer culture fed by media flowing through the channels. Along with SwRI, INCELL, and the Kaunas Lab at the Texas A&M Department of Biomedical Engineering, our goal is to optimize the culture protocols for various sizes of this perfusion reactor to enable the culture of mesenchymal stem cells derived from multiple sources (bone marrow, adipose, etc.) while maintaining the proliferative and differentiation potentials of these cells. Along with the GelMA microcarrier project mentioned above, this bioreactor will maximize the manufacturing capacity of virtually any adherent cell line.
Mimicking the Osteogenic Niche to Repair Bone
Key Personnel: Eoin McNeill, Suzanne Zeitouni (Inactive)
It is widely accepted that human mesenchymal stem cells (hMSCs) are one of the numerous progenitors of bone tissue. In an attempt to replace bone autografts and other sub-optimal, expensive or dangerous bone repair strategies, hMSCs have been intensely investigated for their ability to promote bone healing. In this ongoing NIH-funded project, we are optimizing the methodology to generate clinically relevant yields of maximally osteogenic hMSCs for bone tissue engineering. During this study we developed a method to enhance the ability of the hMSC to differentiate into osteoblasts while retaining their progenitor cell abilities such as rapid expansion in culture, and the ability to engraft into tissues in vivo. This “hybrid phenotype” was achieved through acceleration of canonical Wnt signaling with the small molecule peroxisome proliferator-activated-gamma (PPAR-g) inhibitor GW9662, and we refer to these cells as osteogenically enhanced hMSCs (OEhMSCs). OEhMSCs are highly osteogenic in vivo and in vitro, but an additional characteristic of these cells is the ability to generate large amounts of proteinaceous extracellular matrix that can be purified from cultures. This matrix has inherent osteogenic properties, and serves as an excellent substrate for attachment of osteogenic cells. When implanted with a suitable source of bone forming cells, the matrix accelerates the regeneration of bone tissue at an unprecedented rate. Recently we have developed a matrix that is superior in efficacy to the state-of-the-art and does not require co-administered cells to drive bone healing.
- Our future goals are to optimize approaches for the delivery of the matrix on injectable microcarriers, as coatings for implantable devices and in 3D printed bone analogs.
- Generate matrices from unlimited supplies of stem cells such as induced pluripotent stem cells.
- Perform studies to secure FDA approval for use in human patients.