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Show COLLEGE OF PHARMACY UNDERGRADUATE RESEARCH ABSTRACTS PHENOTYPIC CHARACTERIZATION OF MURINE ADIPOSE-DERIVED STROMAL CELLS ON COLLAGEN OR EXTRACELLULAR MATRICES Taran Packer (David Grainger) Department of Pharmaceutics and Pharmaceutical Chemistry University of Utah The host's foreign body response (FBR) to implants is a leading cause of medical device failure. Recently, combining adipose-derived stromal cells (ASCs) with n e w material device strategies has been pursued with the intention of reducing the FBR by exploiting the immunomodulatory potential of these pluripo-tent stromal cells [1]. In addition to reducing the host immune response to an implantable device, ASCs are also reported to increase the rate of healing around an implant [2]. Unfortunately, like most pluripotent cell types, expansion of ASCs in traditional cell culture is challenging due to loss of its pluripotent pheno-type. Thus, there is a need to develop better cell culture strategies to act as a bridge for therapeutic uses on implants. Improving the ASC culture environment by providing a more native culture surface should maintain the ASC phenotype over an extended culture time, ultimately allowing the incorporation of ASCs into implanted devices to mitigate the FBR. Cultured phenotypes from ASCs grown on tissue culture polystyrene (TCPS) either coated with adipose-derived extracellular matrix (ECM), collagen type I, or uncoated, were compared using molecular and biochemical means. Rat tail collagen (RTC) and porcine adipose ECM were purified using an in house protocol by 1) homogeni-zation 2) hypo and hyper tonic salt solutions 3) surfactant solution 4) lyophilization 5) acid solubilization (0.5 M acetic acid). These solutions were plated onto TCPS at 1 mg/ml for the E C M and 0.5 mg/ml for the RTC by air drying. Genetic markers for ASCs (e.g., CD90 and CD34) were detected by RT-PCR at the time of tissue harvest, indicating that ASCs were present in the harvested stromal vascular fraction (SVF). ASCs were found to have increased proliferation when cultured on both adipose and collagen ECM-coated surfaces compared to TCPS, with the largest proliferation potential shown on adipose ECM-coated surfaces. Cell metabolic activity, as measured by ATP levels, was lowest in the adipose ECM-coated wells when compared to cells cultured on either TCPS or collagen-coated TCPS. These data, when taken in combination, could be indicative of decreased intracellular activity for ASCs cultured on adipose-ECM, and that these cells could be reverting to a purely proliferative state. Future work will include verification of these results and the correlation of trends in these data with ASC phenotyping (through documented ASC cell surface markers) after time spent in culture. Long-term future work will include the jump from 2 D to 3D culture environments and implantation in a living model system to determine ASC ability to affect the host FBR to implanted materials. Lk day 1 day3 day7 I Control 1 Collagen I ECM i Control > Collagen 'ECM day 1 day3 Figure 1: The amount of ATP (AIEIiiE Assay). ATP levels correlate to metabolic activity. Higher ATP levels indicate higher metabolism. Figure 2: The amount of fluorescence as measured by the AJajrar Blue assay. The higher the fluorescence the greater the living cells References 1. H. L. Prichard, W. Reichert, B. Kiltzman. "IFATS Collection: Adipose-Derived Stromal Cells Improve the Foreign Body Response."Stem Cells, vol. 26, pp. 2691-2695,2008. 2. Y.C. Lin, T. Grahovac, O.S Jung, et al. "Evaluation of a multi-layer adipose-derived stem cell sheet wound healing model." Acta Biomater, vol 09, pp. 28-32,2012. |