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Plant cells in plant cell cultures can be used for production of secondary metabolites and recombinant proteins. Producing the desired compounds can be problematic since cells grow slowly, yields can be low and sometimes plant cells do not produce the desired compounds. Yields can be increased by various methods, of which optimisation of growth conditions to favour growth and secondary metabolite biosynthesis is one of various strategies. Light quality is known to have an impact on growth of plants and on accumulation of secondary metabolites. Plants receive information of their environment with photoreceptors, which gives plants ability to alter their morphology and biochemistry to adapt to the prevailing conditions. One of the most important factors involved in controlling morphology and metabolism is activity of bZIP protein HY5, which levels are controlled by degradation by E3 ubiquitin ligase COP1. The photoreceptors are divided to three main groups. A group of Blue/UV-A photoreceptors consists of cryptochromes and phototropins. Phytochromes are photochrome photoreceptors of wavebands of red and far-red. UVR8 photoreceptors are specialized to sense UV-B wavebands. Activated photoreceptors reduce the activity of COP1 individually or inductively. Plant cells contain the same genetic information as intact plants. Object of this study is to investigate effects of different light spectra on plant cell mass pigment accumulation, lipid content and accumulation of secondary metabolites. Additionally, the obtained results can be utilized in designing new artificial light sources to enhance growth and nutritional value of horticultured plants grown under artificial light. VTT's callus cultures established from berries of Rubus (raspberry, cloudberry, arctic bramble) and Vaccinium (lingonberry, bilberry, cranberry) were used in this study. The cell cultures were grown in hormone balanced solid media. For this research Valoya provided four different LED light sources with different spectra, ranging between wavebands 400–800 nm. All berry callus cultures were grown for continuous period of 28–31 days under different light sources. Mass pigments, lipid composition, total phenolic concentration and anthocyanins were analysed from each cell cultures which received different light treatments. Samples were pooled and were by freeze dried and milled. Mass pigments were extracted with acetone and analysis was carried out with UPLC-DAD. Extraction of lipids was carried out with petroleum ether followed with transesterification of glycerolipids and silylation of free fatty acids. The lipid extracts were analysed with GC-MS. Phenolic compounds were extracted with methanol and the extracts were treated with Folin-Ciocalteu's reagent and then analysed with spectrophotometer. Anthocyanins were extracted with acidified methanol and a portion of the extracts were hydrolysed to qualify anthocyanidin moieties of anthocyanins. The extracts and the hydrolysed extract were analysed with UPLC-DAD. Analysis of volatile compounds from each light treated samples was carried out with SPME GC-MS. The obtained results were used to compare concentration differences of the analytes under different light treatments. Correlations between the concentrations of the analytes and different wavebands were possible to establish from the results. Activation of cryptochromes and phytochromes reduced certain lipids that are precursors in LOX-pathway which indicates to increased activity of the pathway. Same wavebands which activated the photoreceptors reduced accumulation of mass pigments, whereas, wavebands of far-red increased the concentrations of mass pigments. In some cases it was observed that small difference in light spectra reduced mass pigment accumulation significantly. The plant cell cultures produced mainly anthocyanins which anthocyanidin moieties were same as in intact plants. Cryptochrome and phytochrome activation increased accumulation of anthocyanins. Yields of anthocyanins can be increased significantly with certain spectra significantly. The effect of light spectra did not have as straightforward effect on total phenolic content. Specie- and linewise differences were observed in light conditions where the highest concentrations of total phenolics were obtained.

Mini-tablets are 1-3 mm in diameter and administered as a single tablet or as a multi-particulate formulation. Mini-tablets are an attractive alternative for conventional solid dosage forms due to the ease of administration and the possibility for combination and individualised drug therapy. In mini-tablet production, good flowability of the formulation is critical as minor variations in die filling can lead to significant changes in mini-tablet weights. In addition, to reduce weight variation, the particle size should not exceed 1/3rd of the die diameter. This study aimed to determine the influence of the granule size on mini-tablet weight variability and content uniformity. The feasibility of direct compression, as well as high-shear wet granulated and roller-compacted formulations, were evaluated. From the nine final formulations manufactured, particle size distribution, Hausner ratio, Carr’s index, angle of repose and flowability were determined. The mini-tablets were made on a rotary tablet press using single punches of 3 mm in diameter. Content uniformity and weight variation of the mini-tablets were determined. The direct compression formulation had the smallest particle size, and the roller-compacted formulation milled through a 1.0 mm and 1.25 mm square screen had the largest particle size. Surprisingly, the RC 0.8 mm grater screen formulation had a very wide particle size distribution and is classified as a very fine blend. The wide particle size distribution might result from a high fill ratio during the milling of the roller-compacted ribbons. The four different high-shear wet granule formulations had a very similar particle size distribution. According to the Hausner ratio and Carr’s index values, the flow properties of the formulations varied between fair and very poor, while according to the angle of repose, the flow properties were between excellent and poor. However, all nine formulations were used to make mini-tablets with acceptable uniformity of mass, mini-tablets were within ± 8 % of the target weight, and none exceeded the 10 % limit set by Ph. Eur. The weight variation is small, as indicated by the low RSD of 1.0-2.9 %. The differences in the weight variation may be attributed to segregation due to particle or granule size and density. This is further supported by the fact that no force feeder or vacuum was utilised in the rotary tablet press, possibly causing re-circulation of the formulation and shearing forces. In addition, the fill level of the feeder might have varied between the nine formulations and affect the weight variation in a way that is not recognised in this study. Only direct compression formulation was within the limits of uniformity of content of single-dose preparations set by Ph. Eur. In the final formulations, the amount of paracetamol was in the HSWG 0.8 mm round screen 98.5 % and in the RC 1.0 mm square screen 97.7 %. These results suggest that the formulations contained an adequate amount of paracetamol, which does not explain why the mini-tablets made from high-shear wet granules did not meet the content uniformity criteria. Furthermore, the weight variation might not entirely explain why high-shear wet granulated formulations performed so poorly in the content uniformity analysis. In summary, that direct compression is a feasible manufacturing method for mini-tablets of 3 mm in diameter. However, further studies are needed on the content uniformity of mini-tablets made using high-shear wet granulated and roller-compacted formulations as these did not meet the content uniformity criterion. In particular, the content uniformity of the mini-tablets made from the high-shear wet granulated formulations was not acceptable, and the reason for this was not identified.

Multiple sclerosis is a progressive inflammatory disease of the central nervous system that affects young adults. The pathological hallmark of MS is the degradation and loss of oligodendrocytes resulting in demyelination. Damage to axons caused by demyelination severely impairs physical function. Currently there is no cure for MS, but current drugs aim to modify the course of the disease and relieve symptoms. However, they are unable to promote the repair of damaged myelin sheaths, and thus new therapies are needed. In this study, the effect of V-MANF on remyelination was investigated in two commonly used experimental toxin models. V-MANF is a modification of the endoplasmic reticulum located protein MANF, which has been found to have neuroprotective and regenerative properties. Additionally, MANF can regulate ER stress, which contributes to demyelination in MS. The effect of V-MANF on lysolecithin-induced demyelination was examined in organotypic cerebellar brain sections from C57B/6 mice. The study was conducted exceptionally using the brains of adult mice because they are a better model for neurodegenerative diseases. However, when analyzing the results, it was found that there was no demyelination in the tissue cultures, so the effect of V-MANF could not be analyzed. In the other study, C57B/6 mice were given dietary cuprizone for six weeks, followed by daily intranasal administration of either V-MANF or vehicle for seven days. Mice were subjected to behavioral experiments, in which a light/dark box test showed that V-MANFs had a potential anxiolytic effect in mice receiving cuprizone. No significant demyelination was observed by immunohistochemical analysis and therefore the effect of V-MANF on remyelination could not be assessed. However, the results of the study can be utilized in the design of further studies.

Since the discovery of ketamine’s antidepressant response, numerous of studies have been observed it to alleviate depressive symptoms rapidly and effectively within hours. This is a significant advantage compared to traditional antidepressants, which take weeks to show treatment efficacy. Ketamine is a N- methyl-D-aspartate receptor (NMDA) antagonist and its underlying mechanism of is proposed to be in its ability to increase synaptic plasticity and this is ultimately believed to improve mood. On a molecular level, the antidepressant effects have been observed to be dependent on the activation of tropomyosin receptor kinase B (TrkB) signalling pathway. However, the antidepressant mechanism of ketamine remains still poorly understood as no new NMDA-antagonist or other rapid-acting antidepressants have been successfully developed for clinical use despite many years of effort. Therefore, some have proposed that the missing pieces of understanding its antidepressant effects might be linked to ketamine’s ability to modify sleep patterns and circadian-related molecules. Ketamine has especially been demonstrated to increase slow-wave activity during the following night of treatment and these changes have been shown to predict the clinical outcome in patients with major depressive disorder (MDD). Slow-wave activity is a low-frequency and high-amplitude wave seen in electroencephalography, which is highly expressed during the deepest stage of sleep, and this has been prominently found to be reduced in MDD patients. Even more intriguing, there are indications that ketamine might increase slow-wave activity also immediately after its administration. During this time, TrkB signalling is observed to became active. Following these molecular findings, we sought to investigate the link between the TrkB signalling pathway and two prominent processes occurring during slow-wave sleep. During slow-wave sleep processes such as (1) reduction of brain’s energy expenditure and (2) the activation of glymphatic system is known to occur. The glymphatic system is as lymphatic-perivascular network, which is responsible for clearing the brain from the metabolic waste. Thus, in this study, our objective was to investigate whether by causing an acute decline in adenosine-triphosphate (ATP) production or by stimulating the glymphatic network, we could activate the same plasticity-related pathways as ketamine is capable of activating in mice prefrontal cortex. The results of this study suggest that acute metabolic reduction can trigger pathways regarding synaptic plasticity. The metabolic inhibitor, 2-deoxy-D-glucose and mercaptoacetate (2DG+MA), was found to phosphorylate the TrkB receptor and its downstream signalling molecules GSK3β and p70S6K, while MAPK was dephosphorylated. These results correlate with the previous findings of ketamine’s effect after its administration. We also found a plasticity-related marker, MAP2, to be heavily phosphorylated by 2DG+MA, indicating 2DG+MA having a surprising role on neuroplasticity. These results are promising indication of understanding the rapid effects of ketamine and might even give important insight to developing novel antidepressants. However, these findings are only preliminary, and more research is needed to directly link antidepressant effects and energy metabolic inhibition together, as our study did not directly investigate antidepressants and depression-like behaviour in mice.

Tablet manufacturing requires both high-quality equipment and powder blend with high flowability and compactability and low segregation tendency. The process is complex and tablet formation process still remains not fully understood. Adequate powder flow is a necessity for the pharmaceutical manufacturing process, i.e., powder flowability and flow properties play a great role when designing manufacturing processes for solid dosage forms. As such, the powder characteristics need to be investigated. However, one property is seldom enough to predict the flowability of a powder in specific processes and different test methods need to be used to fully understand the tableting performance of a particular powder. It is crucial to know how the assessed properties reflect the manufacturing conditions. The need for test batches and the use of empirical testing still exists despite the numerous powder characterization tests available. The main aim of the study was to understand the influence of material properties, flow properties and segregation tendencies on both the processability of a formulation during tablet compression and the critical quality attributes, such as mass, tensile strength and dose uniformity of the final drug product. Additionally, testing of an in-line NIR method to observe the homogeneity of the powder inside the force feeder right before the compression step and transmission Raman as an at-line method for tablet content were also evaluated. A number of powder characterization tests were employed in order to fully understand the impact of the formulation on the process performance. Three formulations with different particle size of the active substance and mannitol were used throughout the study. Both the sifting segregation and fluidization segregation tests’ results predicted the formulations’ tabletability particularly well. Fluidization segregation test predicted the changing composition of the formulation throughout tableting whereas sifting segregation results showed the constantly fluctuating API concentration in the manufactured tablets. Moreover, the Raman results confirmed the tablets of variable content despite the offset caused by the different particle size of the raw materials used. The functionality of the NIR in the force feeder was tested successfully. The residence time distribution could be determined at a sufficient level to point out tablets of a bad quality from the batch on grounds of the NIR data. Results from the powder flow property tests were rather conflicting. Angle of repose, Carr’s index and volume flow rate gave the best characterizing results, whereas the mass flow rate, shear test with higher normal stress in pre-shear gave the worst results, considering the experienced flow character of the formulations. As stated above, different flow property tests may give conflicting result, and hence, it is crucial to know which results are the most relevant ones. Furthermore, the right settings for the test should be known to gain applicable results, best exemplified by the shear cell test.

Heart failure is a major public health problem and a leading cause of mortality worldwide. The most common cause of heart failure is myocardial infarction. Following a myocardial infarction, a large number of cardiomyocytes die and cardiac muscle is replaced by fibrotic scar tissue. Since the adult heart has inadequate endogenous regenerative capacity, loss of muscle tissue often causes a progressive decrease in cardiac function eventually leading to heart failure. At the moment heart transplantation is the only curative treatment for heart failure, but the low number of donor hearts is limiting the use of this treatment option. As current drugs only slow down the progression of the disease, there is a great need for new regenerative treatments. Direct cardiac reprogramming is a new approach for generating cardiomyocytes for cardiac regeneration. Unlike pluripotent stem cell-based strategies, direct reprogramming enables conversion of a terminally differentiated cell type directly into another cell type without first producing a pluripotent intermediate. Due to their abundancy and role in the repair of myocardial injury, fibroblasts represent an attractive starting cell type for direct cardiac reprogramming. Fibroblasts have been directly reprogrammed to induced cardiomyocytes (iCMs) by overexpression of key cardiac transcription factors, microRNAs (miRNA) or by modulating specific signal transduction pathways with small-molecule compounds. Despite successful reports of direct reprogramming both in vitro and in vivo, the efficiency of direct reprogramming remains, however, too low for potential clinical applications. The aim of this M.Sc. thesis work was to establish direct reprogramming of mouse embryonic fibroblasts (MEFs) to iCMs by viral overexpression of cardiac transcription factors Hand2 (H), Nkx2.5 (N) Gata4 (G), Mef2c (M) and Tbx5 (T) and a small-molecule compound screening platform for identifying small-molecule compounds that could enhance the reprogramming efficiency and potentially replace cardiac transcription factors in direct cardiac reprogramming. In accordance with previous publications MEFs were successfully directly reprogrammed to iCMs using both HGMT and HNGMT cardiac transcription factor combinations. The screening platform was tested using the TGF-β inhibitor SB431542, which has recently been reported to increase the cardiac reprogramming efficiency. In line with previous publications, the reprogramming efficiency was significantly increased by treatment with SB431542. Initial tests with other small-molecule compounds did not have a positive effect on the reprogramming efficiency. The results of this M.Sc. thesis work verify previous publications and demonstrate a method for in vitro small-molecule compound screening, which can be used to identify compounds that increase the reprogramming efficiency in direct cardiac reprogramming. However, the results shown here are only preliminary and more replicates are needed in order to confirm the current results. Nonetheless, the results of this thesis work set a foundation for finding small-molecule compounds that in the future might be used to target direct cardiac reprogramming as a regenerative therapy for myocardial infarction and heart failure.

The p53-family consists of three transcription factors, p53, p73 and p63. The family members have similar but also individual functions connected to cell cycle regulation, development and tumorigenesis. p53 and p73 act mainly as tumor suppressors. During DNA damage caused by anticancer drugs or irradiation, p53 and p73 levels are upregulated in cancer cells leading to apoptosis and cell cycle arrest. p53 is mutated in almost 50 per cent of the cancers, causing the cancer cells unable to undergo cell death. Instead, p73 is rarely mutated in cancer cells and because of that could be more viable target for anticancer therapy. The network surrounding the regulation of p73 is extensive and has several potential targets for cancer therapy. One of the most studied is Itch ligase, the negative regulator of p73 levels. Gene therapy directed towards knockdown of Itch ligase is a potential approach but in need for more in vivo proof. p73 has two isoforms, transactivating TA-forms and dominant-negative ΔN-forms. The specific regulation of these isoforms could also offer a possible way for more effective cancer treatment. The literature work includes information of structures, isoforms, functions and possible therapeutic targets of p73. Also the main therapeutic approaches to date are introduced. The experimental part is based on transfection and cytotoxicity studies done e.g. in pancreatic cancer cells (Mia PaCa-2, PANC1, BxPc-3 and HPAC). The aim of the experimental work was to optimize the conditions for effective transfection with DAB16 dendrimer nanoparticles and to measure the cytotoxicity of plain dendrimers and DAB16-pDNA complexes. Also the protein levels of p73 and Itch ligase were measured by Western blotting. The work was done as a part of a bigger project, which was aiming to down regulate Itch ligase (negative regulator of p73) by siRNA/shRNA. Tranfection results were promising, showing good transfection efficacy with DAB16 N/P30 in pancreatic cancer cells (except in BxPc-3). Pancreatic cancer cells showed recovery in 3 days after they were exposed to plain dendrimer solution or to DAB16-pDNA. Measurement of protein levels by Western blotting was not optimal and the proposals for the improvement regarding e.g. the gels and the extracted protein amounts have been done.

Functional in vitro cultured human hepatocytes are needed in different applications in biomedical research. Treatment for liver diseases is usually liver transplantation, but due to the lack of healthy donors, cell therapy using hepatocytes is considered as a better option. Drug industry will also need representative liver models to test metabolic profiles of drug molecules. Primary human hepatocytes are studied in cell therapy and disease modelling, but they have also drawbacks. In vitro they do not proliferate efficiently, and they are short-lived. In vitro differentiated human pluripotent stem cells (hPSCs) to hepatic fate are an alternative for the primary human hepatocytes. Especially human induced pluripotent stem cells (hiPSCs) are widely studied because they are easily available, and they even make personalized therapy possible without problems with ethical issues related to the human embryonic stem cells (hESCs). Differentiation to hepatic fate includes several steps before mature functional hepatocyte-like cells are formed. Hepatocytes are derived from the definitive endoderm (DE) which is one of the germ layers formed in the gastrulation process. Efficient induction of hPSCs into DE lineage would be a good starting point for generating mature hepatocyte-like cells in further hepatic differentiation. Different protocols to differentiate hPSCs in vitro into DE have been published. In vitro cell culture systems should well represent the environment of the target tissue because signals from the environment guide the differentiation. Three-dimensional (3D) cell culture systems are widely studied, because they better mimic the in vivo microenvironment of cells than two-dimensional (2D) cell culture. The aim of the thesis was to study the efficacy of the 3D differentiation of hiPSCs into DE. Before starting the 3D differentiation, differentiation protocol was optimized and the effect of ROCK inhibitor Y-27632 was investigated. Differentiation medium was supplemented with Y-27632 during the whole 6 days differentiation, because survival of the cells and formation of the spheroids were improved, and gene expression studies of pluripotency markers and several DE markers did not show evident effect of Y-27632 on the gene expression of hiPSCs. The main objective in the studies was also to investigate possible differences between different 3D culture conditions on hiPSCs differentiation into DE. Also, the effect of the spheroid size on differentiation was examined. Two different hydrogels were used as a matrix material in the experiments: basement membrane extract (BME) and nanofibrillar cellulose (NFC) hydrogels. Suspension culture was used as a biomaterial-free 3D culture system. Experiments were performed with three spheroid sizes: 200 cells/spheroid, 500 cells/spheroid and 1000 cells/spheroid. Efficacy of differentiation to DE lineage was estimated by studying protein and mRNA expression of some of the DE markers (HNF3B, SOX17, CXCR4, CER1), pluripotency marker OCT4, mesendoderm marker Brachyury and hepatoblast marker HNF4A in the cells. Spheroids differentiated in suspension and NFC were analysed by flow cytometry to get the number of DE positive live cells and dead cells using CXCR4 and 7-AAD double staining. Besides flow cytometry, protein expression of some of the key markers were studied by immunofluorescent staining and further confocal imaging. Viability of the spheroids in BME hydrogel culture were investigated using live/dead staining followed by confocal imaging. BME hydrogel culture was left out from the further experiments due to the morphology of the spheroids and results from viability and protein expression studies. Spheroids in suspension started DE differentiation faster compared to NFC culture. Suspension and NFC cultures yielded high number of double positive cells in flow cytometry and bright fluorescence of other DE markers was seen in the confocal images. NFC hydrogel proved to be a promising 3D culture system by supporting the differentiation of hiPSCs. Flow cytometry results and gene expression studies propose that four days long 3D differentiation would be efficient to produce sufficient number of DE cells. Smaller spheroids showed higher number of DE positive cells than bigger spheroids on day 2 but gene expression studies showed difference in DE marker expression between size conditions rather in later days in differentiation and it was the opposite. Experiments showed signs of more efficient differentiation of the smaller sized spheroids in the beginning of differentiation. But further studies are needed to verify the obtained results and both draw conclusions about the possible differences between different 3D culture systems and explore the best size of the spheroid for hepatic differentiation. However, results obtained from the studies are useful for designing further experiments.

OATP2B1 is a transmembrane transport protein expressed widely in the human body and transports both endogenous compounds and several drugs from outside the cell into the cytoplasm. The abundant expression of OATP2B1 in pharmacokinetically important tissues such as in the intestine, liver, and kidney suggests an important role in the drug absorption and elimination process, although research data on the clinical significance of OATP2B1 is still limited. Several drugs inhibit the function of OATP2B1, creating a risk for drug-drug interactions. OATP inhibition by some inhibitors is time-dependent, which may lead to more potent in vivo effects than expected. In this study, the time dependence of OATP2B1 inhibition by five different drugs was evaluated using OATP2B1-overexpressing HEK293 cells. IC50 values of inhibitors for OATP2B1-mediated uptake of DBF and E1S were determined with and without preincubation for 20 minutes. In addition, the in vivo interaction potential of the inhibitors in the intestine, liver, and other tissues was evaluated by utilizing the FDA and EMA guidelines. All five drugs showed effective and concentration-dependent OATP2B1 inhibition with IC50 values of 0.12– 8.82 µM. Furthermore, the inhibition of OATP2B1-mediated DBF uptake by ticagrelor and atorvastatin was time-dependent, while the effect of pre-incubation remains below the limit for the other inhibitors. The inhibitory effect of ticagrelor continued even after the inhibitor was removed from the inhibition buffer. All five inhibitors showed the potential to cause in vivo OATP2B1 inhibition in the intestine, which could result in decreased absorption of the co-administered substrate drug. About erlotinib, the risk of interaction also appeared in the liver, which could reduce the transfer of the substrate drug to the liver and thus lower its elimination rate. In this study, pre-incubation did not affect the in vivo interaction potential of the inhibitor drugs. The results indicate that drug-induced inhibition of OATP2B1 may be time-dependent and therefore can lead to interactions at lower concentrations than expected. For this reason, evaluating the time dependence would be appropriate when assessing transport protein-mediated interaction risk. The results of this study can be utilized in designing clinical interaction studies and in understanding the results.

Hepatitis C virus disease is transmitted through blood. Chronic hepatitis C causes liver damages such as liver fibrosis, liver cirrhosis, and hepatocellular carcinoma. It is estimated that there are approximately 20 000 - 30 000 patients infected with hepatitis C virus in Finland. For many years pegylated interferon and ribavirin has been standard of care. However standard of care causes side effects and an adequate treatment response can't be achieved with it. There have been effective direct-acting antivirals available on market which are directed against structural proteins and enzymes of the virus from 2014 onward. These second generation direct-acting antivirals are effective, safe and well tolerated. The only disadvantage is the high price of these medicines which restricts them for severe liver damage patients. More information about cost-effectiveness of second generation direct-acting antivirals is needed to support the decision making. The aim of this master thesis is to describe current care, guidelines, and costs of hepatitis C in Finland. Thesis also describes the principles of economic evaluation and systematic literature review. The purpose of the thesis is to assess cost-effectiveness of second generation direct-acting antivirals versus standard of care in treating of hepatitis C by means of systematic literature review and evaluate the quality of cost-effectiveness analyses. Previously published studies were used to analyze the cost-effectiveness of second generation direct-acting antivirals. In total of 435 references were found through systematic literature search. In addition, two studies were found from the bibliographies of already included studies. Altogether 26 studies were included in the systematic review of which 25 were original studies and one was previously published systematic literature review. The most relevant data of the studies was gathered and analyzed. The quality of the studies was assessed by using three checklists. It is difficult to make conclusions about cost-effectiveness of second generation direct-acting antivirals based on previously published reviews because only one review was found through systematic literature search. The incremental cost-effectiveness ratio (ICER) of second generation direct-acting antivirals varied between dominance and 1 135 655 € /QALY compared to standard of care. When compared to another second generation direct-acting antiviral, ICER of second generation direct-acting antivirals varied between dominance and 65 281 € /QALY. It was also analyzed how stage of liver damage affects the incremental costeffectiveness of second generation direct-acting antivirals. The ICER of second generation direct-acting antivirals was between 299 € - 85 195 € /QALY when treating patients with cirrhosis. When treating non-cirrhotic patients, the ICER of second generation direct-acting antivirals was between 2182 € - 177 679 € /QALY.The connection between funder of the study and the ICER of second generation direct-acting antivirals was also analyzed. The ICER was 1717 € - 86 056 € /QALY in studies funded by pharmaceutical company. The ICER was 299 € - 1 135 655 € /QALY in studies funded by other party. Based on the results of the thesis second generation direct-acting antivirals might be cost-effective compared to current standard of care in treating hepatitis C. The cost-effectiveness ratio of second generation direct-acting antivirals is lower in cirrhotic patients than in non-cirrhotic patients. The incremental cost-effectiveness ratio is lower when pharmaceutical company funds a study. The quality of the cost-effectiveness analyses included in the thesis varied greatly which makes it difficult to draw conclusions and interpretate the results. This study has several strengths. First, literature search was conducted systematically and transparently. Second, quality of the reviewed studies included was assessed by care. Finally, reporting of the results is transparent and repeatable. The study has also some limitations. Selection of the reviewed studies, data extraction and quality assessment of the studies was conducted by one person which may increase the possibility of human error.