Host Response to Implantation of A Poly N-Isopropylarylamide Injectable Cell Therapy Vehicle

There is a need to develop novel and effective therapies targeting end-stage peripheral arterial occlusive disease (PAOD). Inducing collateral arteriogenesis is a possible novel treatment that produces a natural bypass for blood flow, a promising solution to the long-term issues seen with current treatments. Regenerative therapies, and progenitor cells specifically, have demonstrated great promise in repair after injury and disease. While most progenitor or stem cells have poor efficacy in this context, muscle progenitor cells, or myoblasts, have encouraging results. Myoblasts enhance arteriogenesis and secrete cytokines or chemokines that recruit monocytes to injury sites. Implanting these adherent cells in a hydrogel construct near natural bypasses in peripheral vasculature increases the size of nearby collateral vessels, pointing to a potentially effective cellular therapy for PAOD. However, many aspects of this novel therapy are yet to be characterized. Given the impact of inflammation and anoikis on transplanted cell survival, one such aspect is the beginning stages of the localized immune response to the implantation of the polymer/cell construct and the impact myoblasts have on this response. This research aims to elucidate the inflammatory response occurring within and locally around poly N-isopropylacrylamide (PNIPAM) polymer constructs post-implantation, focusing on the population and classification of cells within and on the surface of the construct. We hypothesize that the implantation will trigger a local foreign body response (FBR) and recruit multiple immune cell types, primarily macrophage lineage, to the injury site. Cell presence on the construct will be analyzed via confocal microscopy and cell populations within the construct will be typed and quantified via flow cytometry. The goal of this thesis is to characterize the impact of myoblasts in a PNIPAM construct implanted in-vivo in a mouse model on the immune response and use this characterization to help interpret how the construct is modulating the immune response and how we can adjust this response more favorably.