Screening Technology for Tissue Regeneration, 01-R8025Printer Friendly Version
Inclusive Dates: 01/09/09 07/01/10
Background - There is a significant interest in new technologies to help the translation of stem cell research into tissue regeneration therapies driven by an aging population, wound casualties and a shortage of tissue transplants. Current focus on cell-based therapies as a central component of tissue regeneration has stimulated the research on technologies to monitor cell differentiation and the use of those technologies for screening chemical libraries to find new drugs to promote cellular differentiation. Stem cells have a clearly defined morphology that changes as cells differentiate into tissue-specific phenotypes. These changes to cell morphology can be used as a marker to measure cell differentiation that can be monitored by imaging technology. Such technologies will speed up the discovery of new drugs and new materials to promote tissue regeneration. In this project, morphological markers of stem cell differentiation were developed to be used as a screening technology. This tool was used to screen a small library of FDA-approved drugs with the goal of validating this technology.
Approach - This project used an optical microscope technique and an algorithm developed by SwRI to perform a primary screen of large numbers of drugs on morphological differentiation of primary human mesenchymal stem cell using image analysis software adaptable to rapid, automated mass screening. To validate the positively screened drugs, they were further tested with secondary molecular biology screening searching for up-regulation of genes indicative of cell differentiation. Finally, drugs that had been screened by both methods were tested using ex-vivo mouse bones to observe bone growth stimulation by histomorphology, the gold standard test for validating drug candidates as bone anabolic therapeutics. Finally, enhanced skin growth, important in wound healing, was also tested using human skin punches biopsied under an IRB protocol.
Accomplishments - SwRI's morphological visual primary screening and molecular biology secondary screening of FDA-approved drugs led to the discovery of several new drugs that were positive for BMP-2 upregulation, as demonstrated by quantitative polymerase chain reaction (qPCR) assay, and positive on the ex-vivo bone formation assay, as demonstrated by histology. All of the drugs identified during this project are listed as off-patent for their composition of matter. As a result SwRI has initiated the patent application process for new use in bone and dermal wound healing applications. In addition, a manuscript will be prepared for publication to serve as a vehicle to promote collaborations. In this regard SwRI has already initiated collaboration with researchers at Vanderbilt University and sent two pre-proposals to USARMRMC to advance developing these drugs into new applications. To achieve these goals, new formulations will be needed, which fits well with SwRI's core capabilities in the area of drug delivery and formulation. These drugs are also valuable venues to advance recent earmark efforts in the area of wound and scar therapies, and are, in part, a normal progression of previous projects in scar therapies, work that was patented and is ready for publication. Another area where the above-mentioned drugs can be applied is bone fractures and bone orthopedic applications. BMP-2 is a key player in this field of human fractures. The use of these small drugs to promote bone healing is highly needed for civilian and military uses alike. SwRI's strong capabilities in drug delivery and scaffold development are also key assets that will help leverage commercial or government opportunities in this field.