Browsing by Subject "3D cell culture"

Chronic wounds are a worldwide health problem that produce a lot of costs for society and can have a substantial impact on patients’ quality of life. Human adipose stem cells (hASCs) have been studied as a treatment option for chronic wounds as they can induce wound healing in many ways. Extracellular vesicles (EVs) produced by hASCs are a great solution to acquire the benefits of hASCs while avoiding their problems such as possible mutagenicity. HASC-EVs have been found to induce wound healing by for example enhancing angiogenesis and fibroblast proliferation. HASCs can be grown in 2D where the cells attach to the bottom of the cell culture vessel or in 3D where the cells attach to each other and create a spheroid. 2D cell culturing is easy and inexpensive but 3D cultured cells resemble in vivo –like conditions more. Because of these in vivo -like features, hASCs grown in 3D might produce EVs that resemble the properties of host cells in natural environment more than 2D. The aim of this thesis was to compare 2D culture, matrix-based nanofibrillar cellulose (NFC) hydrogel culture, and matrix-free suspension culture in ultra-low attachment (ULA) wells as growing platforms for hASCs and as continuous EV production methods. During culturing, the conditioned media was collected after which, the EVs were isolated, and the EV concentration and size range was measured with nanoparticle tracking analysis (NTA). After culturing, the metabolic activity of hASCs was measured and the cells were collected for immunocytochemistry (ICC) assay, western blot (WB) assay, and for quantitative PCR (qPCR) to examine the stemness and differentiation of hASCs grown in different cell cultures. The hypothesis of this thesis was that the NFC cell culture would produce the best EV yield and the best EVs for therapeutic use. Based on the acquired results, this hypothesis could not be supported. When visually inspecting the cells, all three cell cultures were viable but the metabolic activity of hASCs in NFC hydrogel was low compared to 2D and suspension cultures. Also, the EV, protein and RNA yield were lower in NFC. ICC, western blotting, and qPCR results were inadequate to make a straightforward implication of what cell culturing condition is the best for EV production and they would need repetition and optimization. Looking at the overall results, 2D cell culturing produced the best EV and RNA yield, had the highest metabolic activity and was least laborious cell culturing method which makes it a good option for continuous EV production. Suspension culture on the other hand resembles in vivo -like environment which could possibly produce better EVs for therapeutic use. The metabolomic assays on the EVs would be interesting to perform in the future to examine if the in vivo –like features affect the quality of EVs.