Impact of Ionizing Radiation Dose and Dose Rate on Adipose Stem Cell Function

The use of ionizing radiation within medicine creates an interesting paradox. First, x-rays can be used as an excellent diagnostic tool, allowing doctors to view internal biological structures without having to perform surgery. This can be done thanks to the characteristics of high energy photons, namely excellent penetration depth and various levels of absorption based upon the density of a material. These same characteristics make ionizing radiation a very effective treatment method for cancer. Radiation focused on a tumor will deposit energy when it interacts with a biological structure (e.g. DNA), eventually causing enough damage to kill the cell. That same damage can be done to healthy cells and tissue, slowing the natural healing and repair response of the body. Adipose derived stem cells (ADSCs) are a mesenchymal stem cell line that has been proven to have similar characteristics to bone marrow derived stem cells, except that they much easier to obtain. Within the body, ADSCs act as immunomodulators and assist with the maintenance and repair of tissues. They have been shown to have excellent differentiation capability, making them an extremely viable option for stem cell therapies and regenerative medicine applications. Due to the tissue ADSCs are derived from, they are highly likely to be affected by radiation therapy, especially when treating something like breast cancer. For this reason, the purpose behind this research is to better understand how ADSCs are affected by doses of radiation similar to a single fraction of radiation therapy. We will also explore different dose rates to determine if there is a significant difference in the response of ADSCs. Finally, a method for researching ultra-low doses of radiation will be developed, allowing experimental doses closer to what is experienced from a diagnostic imaging procedure like computed tomography to be performed. The results shown from this research will help fill in the gap regarding how ADSCs respond to radiation therapy relevant doses of ionizing radiation. The potential ADSCs have in the space of regenerative medicine makes them an ideal candidate for study with ionizing radiation, as they are one of the main cell types to promote tissue healing