Bioinseneeria instituut
Selle valdkonna püsiv URIhttps://hdl.handle.net/10062/99556
Sirvi
Sirvi Bioinseneeria instituut Pealkiri järgi
Nüüd näidatakse 1 - 20 26
- Tulemused lehekülje kohta
- Sorteerimisvalikud
listelement.badge.dso-type Kirje , Bismuth as a Desalination Electrode Material(Tartu Ülikool, 2025) Agbomeji, Habeeb Olatunbosun; Grozovski, Vitali, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutAddressing freshwater scarcity and the energy demands of desalination, capacitive deionization (CDI) offers an energy-efficient solution for brackish water treatment by applying low voltages (~1.2 V) to capture ions on charged electrodes. Conventional carbon-based CDI, however, is limited to low salt removal capacities (~15 mg/g). To enhance performance, hybrid-CDI with Faradaic electrodes, such as bismuth (Bi) nanopowders, is explored for high-capacity, cost-effective chloride capture, and possible desalination of the seawater. This study investigates two morphologically different Bi nanopowder electrodes in 0.1 M NaCl, revealing a sequential electrochemical mechanism - Bi to Bi₂O₃, BiOCl, and BiCl(OH)₂. Both samples exhibit near-reversible oxide formation, diffusion-controlled oxychloride production, and surface-confined hydroxylated oxychloride formation, though cathodic irreversibility poses challenges for complete film reduction. These findings highlight Bi electrodes’ potential for sustainable CDI desalination, with given morphology and purity offering significant advantages.listelement.badge.dso-type Kirje , Brain Atrophy and Neuron Loss in the 5xFAD Mouse Model of Alzheimer's Disease(Tartu Ülikool, 2025) Khazhmuratova, Zhanel; Hickey, Miriam Ann, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutThe 5xFAD mouse model is a well-known genetic model of Alzheimer’s disease (AD) that replicates key markers of the disease in humans and is widely used in AD research. However, clear and comprehensive evidence of neurodegeneration in this model is lacking. In this study, serial stereological cryosections from female 5xFAD transgenic and wild-type littermate mice at 9 and 14 months of age were analysed using machine learning-based tools, and the structural and cellular changes were compared between genotypes. We revealed a significant reduction in striatal and cortical volumes at 9 months, followed by hippocampal volume reduction at 14 months. At 9 months, cell detection analysis revealed a significant loss of neurons in the striatum, providing, to our knowledge, the first evidence of neuronal loss in the striatum of 5xFAD mice. These changes precede the emergence of severe cognitive dysfunction in this model and align with imaging data from human AD patients showing that striatal neurodegeneration correlates with the appearance of dementia. Although the striatum is not typically the primary focus of AD research, our findings highlight its important involvement in disease progression and as a target for further research.listelement.badge.dso-type Kirje , Cell-Penetrating Peptide Nanoparticles for Delivery of Splicing-Correction Oligonucleotides and DNA Origami(Tartu Ülikool, 2025) Mazur, Oleksandr; Porosk, Ly, juhendaja; Pooga, Margus, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutCell-penetrating peptides (CPPs) are emerging as versatile, non-viral vehicles for nucleic-acid therapeutics, yet their cargo range and in-cell efficiency remain limited. In particular, most studies have not compared how the same CPP sequence handles cargos of very different size and architecture; moreover, there have been no attempts yet to deliver the DNA origami using the CPPs. Here, we asked how the three PepFect14-derived CPPs — PF14, Peptide 1, and PF14-Lys-Ile9 — perform with small versus bulky nucleic acids. Nanocomplexes were prepared by simple aqueous mixing and characterised by DLS/TEM, giving uniform spheroidal particles 100–160 nm in diameter (PDI ≤ 0.30). Functional delivery was then benchmarked for (i) a splice-correction oligonucleotide (SCO-705), (ii) a fluorescent three-arm DNA-origami probe (Nano-Cy3), and (iii) a luciferase-silencing siRNA embedded in, or tethered to, the same origami scaffold. In HeLa pLuc705 cells, Peptide 1 restored luciferase ~34-fold, exceeding PF14 (24-fold) and PF14-Lys-Ile9 (21-fold), while flow cytometry showed PF14-Lys-Ile9 achieved the highest Nano-Cy3 uptake in U87 cells without a corresponding gain in splice rescue, pinpointing endosomal escape as the bottleneck. With siRNA packed into the native LUC nanohydrogel, PF14-Lys-Ile9 drove the deepest knock-down (~72 %), whereas activity halved when siRNA was supplied as an isolated linker duplex. Overall, Peptide 1 is best suited to delivering small oligonucleotides, whereas PF14-Lys-Ile9 is more effective for larger, origami-based constructs — insights that chart distinct optimisation routes for future CPP nanocarriers.listelement.badge.dso-type Kirje , Characterising a Novel HNH-Domain Containing Bacterial Immunity System From Escherichia coli(Tartu Ülikool, 2025) Aliyeva, Elfi; Mets, Toomas, juhendaja; Abdullah, Minhal, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutBacteria are constantly in danger of being attacked by bacterial viruses - bacteriophages. To combat the threat, bacteria have developed a wide array of intricate and diverse immune systems. Phage therapy’s growing popularity has led to increased interest in bacterial immunity. My thesis investigates one such potential immunity system from Escherichia coli, discovered by our colleagues at Lund University, named Bogomol. It is predicted to be comprised of an HNH-containing endonuclease domain and a C-terminal domain of unknown function. I validated Bogomol as an immunity system acting against certain phages of Straboviridae. This was done by performing efficiency of plating assays and liquid culture experiments against the BASEL phage library. As an attempt to further investigate the triggers of Bogomol, escape mutant experiments were also conducted.listelement.badge.dso-type Kirje , Characterization of Microbial Community Present on Communal Surfaces with Antimicrobial Coatings(Tartu Ülikool, 2025) Mehraliyeva, Laman; Ivask, Angela, juhendaja; Harleen Kaur, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutMicrobial contamination on high-touch communal surfaces poses a risk to human health. While traditional cleaning methods such as disinfection and washing are commonly used, they may be limited by human error, reduced microbial susceptibility, or the need for frequent reapplication. Antimicrobial coatings offer a promising alternative by providing persistent protection through mechanisms that inhibit microbial growth or attachment. Copper is one of the most frequently present materials in currently marketed antimicrobial coatings. The main aim of this study was to examine the bacterial communities on the handles of shopping baskets covered with metallic copper and to compare them with handles that had no copper surfaces. Microorganisms were collected from the handles using moistened cotton swabs, and the collected samples were used to count aerobically growing bacterial colonies. To eliminate the DNA of non-viable bacterial cells from community analysis, propidium monoazide dye (PMA), which is expected to bind the DNA of dead or heavily damaged bacteria, was added to part of the samples. Then, DNA was extracted from the samples, and sequencing libraries were constructed. The microbial communities on surfaces were identified through sequencing of the 16S rRNA variable region and analyzed using statistical tools. The results showed that basket handles coated with copper had significantly fewer aerobically growing bacterial colonies and lower species richness compared to the handles without copper surfaces. Additionally, the microbial taxa present on the surface differed from those found on uncoated handles. Treatment of the surface-collected microbial communities with PMA further influenced the composition of the microbiome. These findings suggest that copper-based antimicrobial coatings may reduce microbial burden and diversity on surfaces, and that PMA treatment is a valuable tool to use in experiments for differentiating between live and dead or significantly damaged microbes in DNA-based studies.listelement.badge.dso-type Kirje , Co-Expression Analysis of Sigma-1 Receptor and Tetraspanins: Insights into the Biogenesis of Sigma-1 Receptor-Enriched Extracellular Vesicles(Tartu Ülikool, 2025) Mathur, Chaitanya; Vāvers, Edijs, juhendaja; Kopantšuk, Sergei, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutSigma-1 receptor (S1R) is a chaperone protein that resides in the endoplasmic reticulum. Recently, S1R has been associated with the generation of extracellular vesicles (EVs). Set of tetraspanins were used as markers for EVs and they were co-express with S1R in mammalian cells using MultiBacMam system. Validation of expression profiles and fluorescent intensities was performed by fluorescence spectroscopy and microscopy. Conditioned cell media was used to isolate EV particles using Tangential Flow Filtration and single-particle analysis with Total Internal Reflection Fluorescence Microscopy was performed to gain insights into the biogenesis of the S1R enriched EVs.listelement.badge.dso-type Kirje , Combinatorial Effect of Histone H3 and H4 Mutations with Deletion of YEATS Domain Protein Sas5 in Saccharomyces cerevisiae(Tartu Ülikool, 2025) Dey, Noah Jabis; Värv, Signe, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutThe single cell eukaryote, Saccharomyces cerevisiae or budding yeast, synthesizes three YEATS domain containing proteins associated with chromatin remodelling and modifying complexes. Previous experiments have shown that deletion of either of the YEATS domain containing proteins, Taf14 or Yaf9, in combination with mutations in the N-terminal tails of histones H3 and H4 is lethal for the cells. In this thesis the aim was to assess the effects of deletion of SAS5, the third YEATS-domain containing protein, in combination with mutations in histones. A decrease in the viability for cells carrying sas5Δ and H3 acetylation and methylation mutations was detected.listelement.badge.dso-type Kirje , Development of an Autonomous Open-Source Inventory Performance Robot for the University of Tartu Library(Tartu Ülikool, 2025) Zvirgzdina, Robina; Raudmäe, Renno, juhendaja; Vunder, Veiko, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutInventory management is crucial for the successful functioning of a venue. Manual inventory management and asset tracking can be time-consuming, dull, and inefficient. In particular, in large-scale libraries, it can take personnel months to perform a single inventory round of all the books. Nowadays, using advanced robotics solutions, it is possible to automate the process and provide more accurate information on the availability and location of the desired book. This results in higher satisfaction for librarians and visitors, as they can successfully find the books of interest. This thesis aims to create an open-source solution that contains a radio frequency identification system for the University of Tartu library. The result is intended to use the Robotont project as a base platform. It should be able to autonomously navigate through library halls while scanning the bookshelves and adjusting the antenna height for it to be at the same level as the books. Simultaneously, it should document the book IDs and their location to produce a heat map containing the most probable location for each book.listelement.badge.dso-type Kirje , Effects of Disruption of Genes With Unknown Function in the C1-Fixing Gene Cluster on a Gas-Fermenting Acetogen(Tartu Ülikool, 2025) Vorontsova, Mariia; Valgepea, Kaspar, juhendaja; Nwaokorie, Ugochi Jennifer, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutGas fermentation is a promising technology for producing chemicals, fuels, and feed proteins from greenhouse gases and solid waste using gas-fermenting microbes. Acetogens are the most attractive biocatalysts for gas fermentation as they can use C1 gases carbon monoxide (CO) and carbon dioxide (CO2) as their sole carbon source using the Wood-Ljungdahl pathway (WLP). Genes encoding WLP enzymes are located in a C1-fixing gene cluster that also contains several genes with unclear function. In this work, the role of two such genes were investigated through gene disruption in the model-acetogen Clostridium autoethanogenum. For this, CRISPR/Cas9n plasmids were constructed and used for knock-out (KO) of the glycine cleavage system H protein (gcvH) and double knock-out (dKO) of gcvH and the first 80 bp of the adjacent acsV gene. Phenotypic characterisation of ∆gcvH in autotrophic batch cultures revealed significant growth defects and altered yields of acetate and 2,3-butanediol (2,3-BDO) compared to the parental LAbrini strain. Additionally, ∆gcvH showed a very long lag phase during growth without yeast extract. Supplementing cultures with glycine shortened the lag phase but did not restore normal growth, suggesting gcvH involvement in glycine synthesis. Notably, the dKO ∆gcvH∆acsV strain failed to grow autotrophically and phenotypic characterisation of heterotrophic batch cultures revealed significant growth defects and higher 2,3-BDO and ethanol product yields compared to LAbrini. Our findings shed light on the potential links between the glycine cleavage system and WLP and contribute towards a better understanding of carbon fixation in acetogens.listelement.badge.dso-type Kirje , Evaluation of Bacterial Viability in Photocrosslinked Hydrogels: Effects of Photoinitiator and UV Exposure on E. coli(Tartu Ülikool, 2025) Kliaus, Dmitrii; Sarıgül, İsmail, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutThe development of targeted delivery systems has significantly enhanced modern therapeutic approaches, particularly in the administration of live biotherapeutics such as probiotics. Hydrogels have emerged as effective carriers for microbial encapsulation due to their biocompatibility, customizable structures, and ability to protect living cells in challenging physiological environments. This study investigates the application of a photopolymerizable hydrogel system, incorporating a photoinitiator, to encapsulate Escherichia coli and examines bacterial viability following UV-induced crosslinking. Two experimental models were utilized: (1) a hydrogel-based encapsulation method wherein E. coli cells were mixed with a hydrogel precursor solution, shaped into pellets, and subsequently exposed to UV light at 365 nm for crosslinking; and (2) a suspension-based assay in which the cells were directly exposed to varying concentrations of photoinitiator and UV light in the absence of hydrogel, facilitating the assessment of phototoxic effects. Bacterial viability and release were quantified through time-point sampling, serial dilution, and colony-forming unit (CFU) analysis. The results indicated that both photoinitiator concentration and UV exposure significantly impact bacterial survival. Although the hydrogel encapsulation offered partial protection, elevated photoinitiator concentrations and extended UV exposure resulted in decreased CFU recovery across both experimental models. This research provide important insights into optimizing photopolymerization parameters for engineered living materials and suggest conditions under which bacterial viability can be preserved during material fabrication. The data obtained from this study can inform the design of probiotic delivery systems and bioactive hydrogel platforms for biomedical applications.listelement.badge.dso-type Kirje , Experimental Setup to Measure the Rate of Oxygen Production from Cyanobacteria(Tartu Ülikool, 2025) Kochiashvili, Elene; Islam, Quazi Saimoon, juhendaja; Kaasik, Laila, juhendaja; Pajusalu, Mihkel, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutThis thesis aims to design and build an experimental setup that includes a novel oxygen sensor developed at Tartu Observatory, algae, specifically Synechococcus, for photosynthesis. This work is motivated by the need to test the oxygen sensor for future implementation in the International Space Station as well as allowing for future calibration of the sensor. The developed experimental setup incorporates control mechanisms to support the growth of Synechococcus cyanobacteria and monitor the oxygen production. The implementation and methodology of devising the required setup is discussed, highlighted key challenges and discovered solutions towards a stable experiment. The results obtained validate the functionality of the oxygen sensor over a large time period of continuous monitoring, verifying its usability in the experimental setup and laying the foundations to the eventual goal of utilizing it for future calibration of the oxygen sensor.listelement.badge.dso-type Kirje , Fragment-Based Design of the Potential AlkBH5 Inhibitors(Tartu Ülikool, 2025) Morozovsky, Yehudit; Ivanova, Larisa, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutBackground. AlkBH5 is a mammalian demethylase responsible for removal of m6A (N6-methyladenosine) modification in RNA. Multiple studies have proven the role of AlkBH5 in several malignancies. Downregulation of demethylase activity using small-molecule ligands has therapeutic potential. Aim. Fragment-based drug design of AlkBH5 inhibitors using different computer-aided drug design techniques. Methods. The library of new potential active compounds was designed using the Core Hopping procedure on the basis of structure analysis of the previously reported active compounds. The interaction between target and designed ligands was evaluated using molecular docking, molecular dynamics simulation, and MM-GBSA calculations. Results. Eight potentially active compounds were identified and selected for the further biological evaluation. Three of them were predicted as the most promising candidates. Conclusion. The study successfully implemented fragment-based methods of computer-aided drug design to identify potential compounds that can be active against AlkBH5.listelement.badge.dso-type Kirje , GenePointer - A Software for Automated Identification of Resistance Markers in Bacterial Genomes(Tartu Ülikool, 2025) Roosimaa, Aleksander; Remm, Maido, juhendaja; Aun, Erki, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutAntimicrobial resistance has been a growing threat on the horizon for more than 70 years now, and recent improvements in sequencing technology and bioinformatics tools are making it easier to analyze bacterial genomes. To add upon the already existing functionality of PhenotypeSeeker, a program for phenotype prediction from genotypes, the author created the resistance marker identification pipeline, GenePointer. The program aims to identify the elements in bacterial genomes most associated with their resistance phenotypes, using mapping and alignment approaches and is made to provide insight into novel associations to make the study of resistance mechanisms faster and more efficient. The program managed to identify some of the resistance associated genes in two of the three species and antibiotic combinations analyzed. However, the current version of GenePointer did not identify any novel associations and lacks the statistical power to identify all the known resistance genes. The program in its current form is useful for analyzing and summarizing the resistance associated elements in large numbers of genomes at a time and has potential in future developments to improve on the detection of associations.listelement.badge.dso-type Kirje , Graphical Programming Interface for ROBOTONT, an Open-Source Educational Robot(Tartu Ülikool, 2025) Khan, Usman Ali; Kruusamäe, Karl, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutThis thesis demonstrates the development of a Blocky-based graphical programming interface as a visual programming language. It enables the control of Robotont, a research and educational mobile robot, through ROS (Robot Operating System). This research approach shows how Google Blockly can lower the complexity of robotics programming for non-expert programmers. The system developed through a design-based approach focuses on simplicity while reducing the technical barriers (ROS implementation and complexity). The key results of this study are a Blockly web app that can create custom blocks for Robotont control and offers a complete solution for ROS communication and robot simulation. This work, due to its accessibility, has the potential to be a framework for robotics education and training, and emphasizes the importance of human-robot interaction.listelement.badge.dso-type Kirje , Identifying Microproteins with Genetic Association Data(Tartu Ülikool, 2025) Savchak, Sviatoslav-Oleh; Alekseienko, Anastasiia, juhendaja; Abner, Erik, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutThe annotation of the human genome is an ongoing process, continually refined as new functional elements are discovered. In recent years, regions previously classified as long non-coding RNAs have gained attention as many of them contain sequences that are actively translated. In this work, we mapped single-nucleotide variants (SNVs) listed in the GWAS Catalog to 7,264 previously undescribed open reading frames (ORFs) identified from the human genome. From this analysis, we identified six final microprotein encoding candidates that are likely to be associated with diseases or traits linked to their corresponding SNVs. These findings will hopefully contribute to the expanding functional annotation of the human genome and highlight the potential biological relevance of previously overlooked potential new microgenes.listelement.badge.dso-type Kirje , Impact of Archaic Introgression on the Abundance of Circulating Inflammatory Proteins in Modern Humans(Tartu Ülikool, 2025) Rostam Nejad, Roza; Dannemann, Michael, juhendaja; Yermakovich, Danat, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutArchaic introgression refers to the transfer of genetic material from archaic hominins such as Neanderthals into ancestors of modern humans. This admixture has left detectable introgressed variants in present-day human populations. Expanding studies suggest that these introgressed variants may affect the range of phenotypic traits, including immunity and inflammation. In this study, we investigated the effect of such introgressed alleles from Neanderthals on circulating inflammatory protein levels in plasma. To do so, we combined a curated archaic introgression map with genome-wide association summary statistics from protein quantitative trait loci (pQTL) studies. We identified 849 archaic SNPs that overlapped with the pQTL signals. From these, 21 archaic alleles, with the strongest association within 1Mb genomic regions, were chosen for further functional annotation. Two variants were found in regions linked to MMP10 and IL18 genes and several introgressed SNPs were associated with protein levels such as CCL25, TNF-β, CCL23, and CCL19 which are involved in autoimmune and inflammatory diseases. These findings contribute to the growing understanding of how archaic DNA continues to shape immune function in modern humans.listelement.badge.dso-type Kirje , Investigation of the Atomic Layer Deposition Principles: Effects of Growth Parameters on SiO2 Thin Films Using Hexakis(Ethylamino)disilane (AHEAD) as a Silicon Precursor(Tartu Ülikool, 2025) Tolbin, Sergei; Jõgiaas, Taivo, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutThis thesis investigates the deposition of silicon dioxide (SiO₂) thin films using Atomic Layer Deposition (ALD), with a focus on optimizing process parameters to improve film thickness, uniformity, and chemical composition. Hexakis(ethylamino)disilane (AHEAD) was used as the silicon precursor, and ozone as the oxidant. The study systematically examines the effects of growth temperature, precursor evaporation temperature, and pulse durations on film properties, with characterization performed using ellipsometry and X-ray fluorescence (XRF). This work contributes to a better understanding of the ALD process using the AHEAD precursor and provides practical guidance for tuning deposition parameters to fabricate high-quality SiO₂ films for semiconductor and nanotechnology applications.listelement.badge.dso-type Kirje , Iron and Nitrogen Doped Hierarchical Porous Lignin-Derived Carbons as Oxygen Reduction Reaction Electrocatalysts(Tartu Ülikool, 2025) Meira Chaves Barbalho, Vitor; Lilloja, Jaana, juhendaja; Tammeveski, Kaido, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutNon-precious metal Fe-N-C electrocatalysts, which can be used as cathode materials for oxygen reduction reaction in an anion-exchange membrane fuel cell were synthesized and investigated by electrochemical and physicochemical methods. The carbon, iron, and nitrogen precursors used to synthesize the electrocatalysts were lignin, iron(II) acetate, and 1,10-phenanthroline, respectively. To obtain the hierarchical porous carbon support, lignin was carbonized using magnesium nitrate hexahydrate as template via high-temperature pyrolysis. Several pyrolysis temperatures (800-1100 °C) were employed to find the optimal carbonization temperature. Iron and nitrogen doping was performed for all carbon materials through flash pyrolysis at 800 °C. The electrocatalytic performance of the prepared Fe-N-C catalyst materials toward the oxygen reduction reaction was studied and compared using the rotating disk electrode method. The physicochemical properties of the catalyst materials were investigated by various analytical methods, namely scanning electron microscopy, scanning transmission electron microscopy, N2 physisorption, X-ray photoelectron spectroscopy, and Raman spectroscopy.listelement.badge.dso-type Kirje , Pilot In Vitro Study of Dexamethasone-Induced Immunomodulation in Murine Splenic T Cells(Tartu Ülikool, 2025) Tyran, Violetta; Chinna Susan Philip; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutGlucocorticoids (GCs) are key hormones in stress response and chronic elevations from chronic stress or prolonged therapeutic use accelerates immune aging and dysfunction. To dissect their direct, time- and dose-dependent effects on T cells, we established an in vitro model in which murine splenocytes were cultured with graded concentrations of dexamethasone (a potent, synthetic GC) and analyzed by 22-color spectral flow cytometry over 24, 48, and 72 hours. Dexamethasone caused a progressive, dose-dependent decline in overall viability and absolute CD4⁺/CD8⁺ T cell counts, transiently increased proliferation (Ki-67) at 48 hours before inducing collapse and apoptosis, and modulated activation (CD69, CD25) and exhaustion (PD-1) markers. Memory and naïve T cell subsets were especially vulnerable, whereas low-dose dexamethasone selectively enriched regulatory (CD4⁺Foxp3⁺) and Th1 (CD4⁺Tbet⁺) subsets. Effector cytokine production (IFN-γ, TNF-α) was markedly suppressed in a dose- and time-dependent manner. This platform thus provides a robust tool for exploring GC-driven immunosenescence, GC resistance mechanisms, and strategies to restore T cell function after chronic GC exposure.listelement.badge.dso-type Kirje , Review of PF14 Analogs: Cell-Penetrating Peptides for Nucleic Acid Delivery(Tartu Ülikool, 2025) Chuduk, Ulyana; Porosk, Ly, juhendaja; Pooga, Margus, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Bioinseneeria instituutEffective nucleic acid based drug delivery is a key challenge in translating gene therapy to clinical practice. Cell-penetrating peptides are the promising tool for delivery of nucleic-acid-based therapeutics into the cells both in vivo and in vitro. New analogs of the well-known CPP - PepFect14 - were created by fatty acid and amino acid residue modifications with the aim of optimizing complexation of CPPs with nucleic acids, stability of CPP/siRNA complexes and efficacy of transfection in the glioblastoma cell line - U87MG. Computational methods, Luciferase expression for evaluation of transfection efficiency, complexation and stability measurements by nucleic acid intercalating dyes, dynamic light scattering analysis, zeta potential measurements and viability assays were implemented for comprehensive research of the PF14 analogs. The study revealed two PF14 analogs, that formed well-defined nanoparticles with siRNA, which were stable against degradation, efficient for siRNA transfection, and didnot impair cell viability.