14:15-14:40: Milla Ylimartimo
Humoral and Cellular Immune Responses induced by Intramuscularly administered Enterovirus 2A and 3C Protease Antigens
Abstract: Enteroviruses are one of the most common human infecting pathogens worldwide. They are responsible for a wide range of diseases, from common cold to more severe infections, and they are also associated with the development of chronic diseases such as type 1 diabetes. Currently, there are only two approved vaccines for enterovirus: those targeting polio and EV71. Traditional inactivated vaccines face challenges due to the serotypic variability and new approaches are needed. 2A and 3C proteases are found across all enterovirus species, which makes them highly conserved. They are involved in multiple infection pathways, making them key players in enterovirus infection. The novel therapeutic approaches are focusing on finding inhibitory compounds to these proteases, but there is no research about using the proteases as antigens themselves. In this research, humoral and cellular immune responses on mice induced by 2A and 3C vaccines were determined using FluoroSpot and ELISA immunological assays. Additionally, conservation analysis was done between the proteases and CVB1 - 6 serotypes. Both vaccines induced high total IgG and IgG1 responses, but low IgG2a responses were detected only with 3C protease vaccination, and no cellular immune activation was observed. These findings support future advances in EV vaccine and antiviral drug development.
Supervisors: Saana Soppela (tuni), Minna Hankaniemi (tuni), Varpu Marjomäki (jyu)
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14:40-15:05: Tuuli Luimula
Fluorine free ion-exchange membranes on vanadium-based flow batteries
Abstract:
The growth of using renewable energy solutions like wind and sun, has increased the need for energy storage systems. VRFBs are promising candidates for ESS technologies. Ion exchange membrane is a critical component for VRFBs and most commercially used membranes are Nafion based membranes. Due to Nafions cost, vanadium ion crossover problem and fluorine’s environmental problems, alternative metal-organic frameworks (MOF) based composite membranes have been studied. Most promising MOFs for ion exchange membranes are UiO-66 and its derivatives, MOF-801, MOF-808 and MIL-101(Cr) and its derivatives.
In the experimental section, a total of 27 products were synthesized: one UiO-66 compound, 10 UiO-66-NH2 compounds, and 16 UiO-66-SO3H compounds. The goal was to optimize and scale up the synthesis of UiO-66-NH2 and UiO-66-SO3H compounds. The products were characterized by using powder diffraction and infrared spectroscopy, and their thermal stability was examined through thermogravimetric analysis. Electrolyte was analyzed via ultraviolet visible (UV-VIS) spectroscopy. Additionally, three membranes were fabricated: one pure chitosan membrane and two chitosan-UiO-66-NH2 (15 wt-%) + UiO-66-SO3H (6 wt-%) membranes. The membranes were characterized using powder diffraction. The synthesis of UiO-66-NH2 was successfully scaled to the gram scale, but the scaling of UiO-66-SO3H was unsuccessful due to the lack of crystallinity despite smaller-scale syntheses being successfully carried out. The membrane synthesis did not produce viable membranes that could be tested in a vanadium redox flow battery single cell system. Due to time constraints in the experimental work, it was not possible to prepare new membranes, and VRFB single cell testing of the membranes was not conducted.
Supervisors: Manu Lahtinen, Samu Forsblom
15:05-15:15: BREAK
15:15-15:40: Thiwangi Rajapaksha
Title : Reducing domain number and increasing domain size in self-assembled DNA origami lattices
Abstract
Metamaterials are one of the trending research fields since they exhibit exceptional properties depending on the fabrication process, like materials with negative refraction index. To achieve these properties, it is crucial to go on the nanoscale, and DNA origami has been renoverd for this purpose because of its self-assembly. These origami structures can be further assembled into fishnet-type lattices, which can be used as a mask for the DNA-assisted lithography method to fabricate metamaterials. For this purpose, it's necessary to work on the silicon surface since the mica surface is not applicable for the lithography. This research was carried out to optimize the surface coverage and domain size of the fishnet-type DNA origami lattices.
The cross shaped twist corrected Seeman tile design was used as a DNA origami structure. DNA origami self-assembly on silicon surfaces depends mainly on the ratio of divalent and monovalent ion concentrations, incubation temperature and time, and the number of blunt end interactions. According to the results obtained from the research, Na⁺ ions as a monovalent ion concentration were found to be the best as reported in literature at 400 mM, and the ratio of Ca²⁺ to Mg²⁺ ions was found to be best as 9:1 in a total 10 mM concentration. The incubation temperature depends on the number of blunt end interactions; 12 and 8 blunt end (BE) designs show good surface coverage at 300C, while it is 150C for the four BE designs. The optimal incubation time was found as 2 hours. Gradual increase of origami concentration with intervals didn’t help to reduce the number of nucleation points. Adding a small amount of Ni²⁺ ions into the solution helps to increase the domain size of origami lattices, and the largest domain was found to be ~ 5.3 µm². The best surface coverage was found to be 81% with a 12 BE design with the above-mentioned parameters. Both of these analyses were done by using FIJI software for AFM images. These results can be used to continue the DNA assisted lithography process.
Supervisors: Jussi Toppari, Heini Järvinen
