Browsing by study line "Biofarmasia"

Endothelial dysfunction is a common characteristic of several diseases including diabetes mellitus, coronary heart disease and stroke. Healthy endothelium ensures vascular homeostasis, regulation of blood flow and the exchange of oxygen and nutrients, as well as immune cell filtration to the surrounding tissues. In many cases, endothelial dysfunction results in ischemia in the surrounding tissues impairing cellular regeneration mechanisms, which can lead to tissue necrosis in the worst case. Therapeutic angiogenesis via stem cell transplantation aims to restore tissue blood flow and thus aid in tissue regeneration and restoration of a functioning tissue. Adipose derived stem/stromal cells (ASC) are a stem cell population with a multilineage differentiation ability. They have been shown to differentiate towards adipogenic, osteogenic, chondrogenic, myogenic and neurogenic lineages among others. Their easy obtainability from liposuction material and abundance in the adipose tissue makes them an especially practical and favorable cell option for stem cell research. In angiogenesis research, ASCs are commonly used in a co-culture with an endothelial cell (EC) type such as human umbilical vein endothelial cell. ASCs secrete extracellular vesicles (EV) that are small membrane bound vesicles with a diameter ranging from 40-1000 nm, and which have the ability to alter the behavior of target cells through their cargo. EV cargo consists of microRNAs, messenger-RNAs and proteins, and the EV cargo of ASCs has been shown to have proangiogenic effects. The aim of this work was to review what is currently known about ASC ability to promote angiogenesis through paracrine secretion and differentiation into endothelial cells or pericytes, interactions between ASCs and endothelial cells in the angiogenesis promoting process and the role of ASC extracellular vesicles in promoting angiogenesis. The methods for this work were database research of related articles using scientific databases and search engines, article categorization and reading, and finally manuscript production. It can be concluded from the current literature that a co-culture environment of ASCs and an endothelial cell type supports the formation of tube-like structures in vitro. Additional insulin like growth factor 1 in culture medium enhances the expression of angiogenesis-related growth factors in both cell types via PI3K/AKT signaling pathway. Further, the activation of platelet derived growth factor receptor β supports ASC ability to promote vascular network formation. On the contrary, the presence of ASC secreted activin A results in the inhibition of vascular network formation. ASCs can differentiate into endothelial cells particularly in three-dimensional culture conditions. In addition, fibroblast growth factor 2 and the activation of the AKT-pathway are crucial for endothelial differentiation. In addition, ASCs have the ability to differentiate into pericytes and assume a stabilizing role on the outside of the microvessels. Concerning ASC derived EVs and their cargo, miR-31, miR-125a and miR-126 have proangiogenic effects in vitro and in vivo. Proangiogenic miRNAs in ASC EV cargo are miR-181b-5p and the let7-family, out of which miR-181b-5p upregulates vascular endothelial growth factor and hypoxia-inducible factor 1α and let7-family influences tube formation ability of ECs. In vivo, ASC derived EVs support fat grafting, enhance wound healing both in healthy and diabetic environment, and provide cardioprotection. Therefore, ASC EVs show potential for therapeutic angiogenesis but currently there is a lack of clinical trials in EV research.

Viral promoters are an essential part of a normally functioning virus. Their main task is to drive the transcription of genes which govern hijacking of cell function and replication of viral particles. In addition to supporting normal function of a virus, they can be used to drive the transcription of transgenes which can be used in different therapies. In oncolytic therapies, transgenes can be used to prime the host system against neoplasms which has been shown to generate long term anti-tumour immunity. Human adenoviruses (Ad) are commonly used as a platform for oncolytic virotherapies. Human Ad’s replicate poorly in mouse tumour cell lines, yet some promoters, which are included in the viral constructs to drive the transcription of beneficial transgenes, are able to function. Currently it is unknown whether E3, the native promoter of adenovirus 5 of the E3 region, is capable of functioning in murine cell lines. In this thesis we study whether human cytomegalovirus promoter (CMV) and E3 differ in their efficacy to drive the transcription of the mOX40L and mCD40L transgenes. In the experimental part of this thesis, we compared the efficacies of two viral promoters, AdE3 and AdCVM, in transcribing mOX40Land mCD40L in vitro. Efficacy of transcription was assessed through immunofluorescence and flow cytometry in human and murine cell lines. Furthermore, the effects of promoters on viral infection, killing and replication were evaluated in burst assay and the colorimetric MTS proliferation assay. MTS and burst assay were conducted to confirm if viral infection, killing and replication occurs in human and murine cell lines. Both AdE3 and AdCMV were able to infect and kill human cell lines and cell viability decreased in correlation to the number of viral particles used. In murine cell lines, no decrease in cell viability was detected in the 4T1 cell line. In burst assay, viral replication was observed for both AdE3 and AdCMV in the human MDA-MB-436 cell line. In murine CT26 cell line, no replication was observed for AdE3 or AdCMV constructs. Immunofluorescence assay was performed to visualize transgene expression and localization. Results indicated that mOX40L was localized on cell surface while mCD40L was detected both outside and inside of the cytosolic compartment. Flow cytometry results revealed that both AdE3 and AdCMV constructs are capable of efficiently transcribing mOX40L in human cell lines. In the flow cytometry results for AdE3, two large cell populations with different fluorescence intensities were detected. AdCMV lacked this feature which is postulated to be due to higher lytic activity of the viral construct. In murine cell lines, HCMV could produce mOX40L, but production in murine cell lines was severely attenuated compared to human cell lines. mOX40L produced by the AdE3 construct did not differ from the baseline and was deemed incapable of producing mOX40L in murine cell lines. For the purpose of studying novel virotherapeutics the results of this thesis would indicate that human CMV can be used to drive expression of transgenes in murine cell lines. Despite this, it is preferable to use host specific viruses and promoter sequences for a better translation between mice and humans. Viruksen promoottorit ovat keskeisessä osassa toimintakykyisessä viruksessa. Virus promoottorin päätarkoituksena on geenien transkriptio, mitkä vastaavat solun keskeisten toimintojen kaappaamisesta ja virus partikkeleiden replikaatiosta. Näiden toimintojen lisäksi promoottoreita voidaan käyttää transgeenien transkriptiossa, mitä voidaan hyödyntää sairauksien hoidossa. Onkolyyttisissä terapioissa transgeenejä voidaan käyttää virittämään kehon immuunipuolustus taistelemaan kasvainkudosta vastaan. Ihmisen adenovirusta käytetään usein onkolyyttisten viroterapioiden alustana. Ihmisen adenovirus (Ad) replikoituu hyvin heikosti hiiren syöpäsoluissa, mutta osa adenovirukseen sisälletyistä eksogeenisistä promoottoreista, joita käytetään terapeuttisten transgeenien transkription ajamiseen, kykenee toimimaan ja tuottamaan haluttua proteiinia. Tällä hetkellä ei tiedetä, kykeneekö E3, joka on adenoviruksen E3 lokuksen promoottori, toimimaan hiiren solulinjoissa. Tässä tutkielmassa selvitämme ihmisen sytomegalovirus promoottorin (CMV) ja E3 eroa niiden tehossa ajaa mOX40L ja mCD40L transgeenien transkriptiota. Kokeellisessa osuudessa vertailimme kahden virus promoottorin, E3 ja CMV, eroa niiden tehossa ajaa mCD40L ja mOX40L transkriptiota in vitro. Transkription tehoa tutkittiin immunofluoresenssin ja virtaussytometrian avulla ihmisen ja hiiren syöpäsolulinjoissa. Tämän lisäksi promoottorien vaikutusta virus infektioon, replikaatioon ja kykyyn tappaa soluja arvioitiin burst kokeella ja kolorimetrisellä MTS menetelmällä. MTS ja burst kokeiden avulla varmistettiin AdE3 ja AdCMV virusten kyky infektoida, tappaa ja replikoitua ihmisen ja hiiren syöpäsolulinjoissa. Sekä Ad3 ja AdCMV todettiin kykenevän infektoimaan ja tappamaan ihmissyöpäsoluja ja solujen viabiliteetin lasku korreloi virus partikkeleiden määrän kanssa. Hiiren 4T1 syöpäsoluissa ei todettu solujen viabiliteetin laskevan. Burst kokeessa havaitsimme sekä AdE3 että AdCMV kykenevän replikoitumaan ihmisen MDA-MB-436 solulinjassa. Hiiren CT26 solulinjassa kummankaan viruksen ei havaittu kykenevän replikoitumaan. Immunofluoresenssi kokeessa visualisoimme transgeenien ilmentymisen ja paikantumisen. Tulokset osoittivat, että mOX40L paikantui solun pinnalle. mCD40L havaittiin puolestaan sekä solun ulkopuolella että sytosolissa. Virtaussytometria kokeen tulokset osoittivat, että sekä AdE3 ja AdCMV pystyivät tehokkaasti ilmentämään mOX40L ihmisen solulinjoissa. AdE3 virtausytometria tuloksissa löydettiin kaksi solupopulaatiota, joilla oli toisistaan poikkeavat fluoresenssi intensiteetit. Tätä ilmiötä ei havaittu AdCMV:lla infektoiduilla soluilla, mikä saattoi johtua korkeammasta lyyttisestä aktiivisuudesta. Hiirisolulinjoissa CMV kykeni ilmentämään mOX40L, mutta transkription teho oli selvästi alhaisempi verrattuna ihmissolulinjoihin. E3 promoottorin ilmentämä mOX40L ei eronnut kontrollista ja sen todettiin olevan kykenemätön tuottamaan mOX40L hiirisolulinjoissa. Tuloksemme osoittavat, että ihmisen CMV promoottori kykenee ilmentämään transgeenejä hiiren 4T1 ja CT26 solulinjoissa. On kuitenkin huomattava, että isäntälajille natiivien virusten ja promoottorien käyttö olisi tarkoituksenmukaisempaa tulosten käännettävyyden kannalta hiiristä ihmisiin.

Background: Alzheimer’s disease (AD) is a worldwide challenge for health care professionals and researchers. Every year, AD causes dementia for millions of patients. No preventive or curative medication is available despite continuous research. Amyloid-beta (Aβ) deposits in brain are one of the main pathological findings in AD. Accumulating Aβ peptides are thought to be the reason behind further disease progression. If the Aβ accumulation could be restricted or Aβ degradation increased their toxic effects would be prevented. Soluble oligomers and protofibrils are the most toxic species of Aβ. Most of the Aβ targeting drugs developed so far have not specifically targeted these toxic species. Neprilysin (NEP) is a major Aβ degrading enzyme that targets mostly the smallest species (monomers and dimers) of Aβ. Another common challenge for protein drugs has been passing the blood-brain barrier (BBB). Different strategies, such as utilising transferrin receptor (TfR) mediated transcytosis, have been studied for drug transport. For example, a rat anti-mouse TfR antibody, 8D3, or its fragments can be used for drug transportation. Objectives: To produce a recombinant protein, sNEP-scFv8D3, combining soluble NEP and single chain variable fragment of 8D3. Testing its ability to degrade different species and isoforms of Aβ in vitro and study in vivo brain uptake. Evaluate whether it is a promising model for future AD treatments. Methods: The recombinant protein was expressed in Expi293 cells and purified with affinity chromatography. The TfR binding was studied with TfR ELISA and enzymatic activity with MCA assay. Aβ ELISA was used for determining the Aβ degradation. Recombinant protein was compared to sNEP. In in vivo studies the brain uptake and blood half-life of radiolabeled sNEP-scFv8D3 of were studied on NLGF mice. Immunohistochemical analyses of brain cryo sections were done to evaluate the co-localisation of Aβ aggregates and sNEP-scFv8D3. Results and discussion: sNEP-scFv8D3 bound to TfR and showed similar enzymatic activity as sNEP. Both sNEP-scFv8D3 and sNEP were able to degrade monomeric Aβ-40 and Aβ-42 but no significant effect was seen on larger aggregates. In mice brain, sNEP-scFv8D3 was detected in same areas as Aβ aggregates. Compared to sNEP, our recombinant protein had better brain uptake. The blood half-life of sNEP-scFv8D3 was approximately 9.5 h and it was cleared fast from the brain. Already 6 h post injection, levels in the brain had dropped more than by half. Further studies are needed to determine whether sNEP-scFv8D3 is effectively transported across the BBB and if it can reduce brain Aβ levels in vivo. Conclusions: In the future, sNEP-scFv8D3 or its improved version could be used at the earliest stages of AD to prevent disease progression. Since sNEP-scFv8D3 degrades only small Aβ aggregates it could be combined with another drug targeting larger oligomers. Together they would decrease the total Aβ deposition in brain.

Background and objectives: Cancer is one of the leading causes of death worldwide, and resistance to current treatments demands the continuous development of novel cancer therapies. Cancer immunotherapy aims to induce anticancer immune responses that selectively target cancer cells. Viruses can also be harnessed to elicit tumor-specific immune responses and to improve the response rates of other concomitant cancer therapies. The purpose of this study was to develop a novel viral vector-based cancer vaccine for intratumoral immunotherapy. By using the previously developed PeptiENV cancer vaccine platform, the vector viruses were coated with cell-penetrating peptide (CPP) sequence-containing tumor peptides in an attempt to further drive the immune responses elicited by the vector against cancer cells. The efficacy of the PeptiENV complex as a cancer vaccine was assessed by following its effects on tumor growth and the development of local and systemic antitumor immune responses. Methods: The PeptiENV complex formation was assessed by a surface plasmon resonance (SPR) analysis. Dendritic cell (DC) activation and antigen cross-presentation were studied using the murine JAWS II dendritic cell line. The development of cellular immune responses against tumor antigens was first studied by immunizing mice with the PeptiENV complex. The antitumor efficacy and immunity of intratumoral PeptiENV administration were then studied using the murine melanoma models B16.OVA and B16.F10.9/K1. In addition to intratumoral PeptiENV treatment, some of the B16.F10.9/K1-implanted mice were also treated with an anti-PD-1 immune checkpoint inhibitor (ICI) to study the PeptiENV complex as a biological adjuvant for ICIs. Results: The SPR analysis confirmed that CPP-containing peptides can be stably anchored onto the viral envelope of the viral vector. The in vitro results showed that the PeptiENV complex does not hamper the presentation of antigens at the surface of DCs. Additionally, the viral vector was found to activate DCs seen as a change in the cells’ morphology and surface protein expression. Immunizing mice with the PeptiENV complex induced a robust antigen-specific cytotoxic T cell response. Upon intratumoral administration in vivo, the PeptiENV cancer vaccine was not capable of inducing tumor growth control against B16.OVA melanoma, although it did still elicit robust systemic and local antitumor T cell responses. In the treatment of B16.F10.9/K1 melanoma, however, the PeptiENV complex induced efficient tumor growth control, which resulted in a significant survival benefit. Additionally, co-administration of anti-PD-1 resulted in an additive therapeutic effect. Discussion and conclusions: The present study describes a novel, highly immunogenic viral vector-based cancer vaccine that has the potential to be used as an adjuvant treatment for ICI therapy. Subsequent studies could be conducted to gain a deeper understanding of the immunological mechanisms underlying the antitumor efficacy of the cancer vaccine complex. Moreover, this novel PeptiENV complex could also be further developed as an infectious disease vaccine platform against emerging pandemics. However, the effects of pre-existing antiviral immunity on the efficacy of the cancer vaccine should be explored in future studies.

Immune checkpoint inhibitor (ICI) therapy aims to enhance the endogenous immune response against tumour cells, and it has become a potent treatment option for various types of cancers. Despite the promise of ICIs, most patients do not respond to the treatment. The primary limitation of ICI therapy is the immunosuppressive tumour microenvironment (TME), which is characterised by the lack of tumour- infiltrating cytotoxic T cells (CTLs) and the presence of immunosuppressive cells, such as tumour- associated macrophages (TAMs). A promising immunotherapeutic strategy that can promote antitumor immunity is oncolytic virus (OV) therapy. OVs can selectively replicate in and kill cancer cells, leading to the release of immunostimulatory molecules. These molecules can induce local inflammation and prime and recruit CTLs to the tumour site. In addition, OVs can also be used as a delivery platform for immunostimulatory transgenes that can further enhance the activation of anti-tumour immune response and help to overcome the immunosuppressive TME. Another strategy used to support anti-tumour immune responses and overcome immunosuppressive TME is epigenetic therapy. Epigenetic therapy can reprogram both cancer and immune cells towards a less immunosuppressive phenotype, thus helping to overcome the limitation of immune checkpoint therapy. The aim of this study was to generate a novel oncolytic adenovirus armed with epigenetic modifying transgene (EpiCRAd) to overcome the immunosuppressive TME and enhance the anti-tumour immune response. We tested its efficacy and immunogenicity in vitro and in vivo using a murine triple-negative breast cancer model. We demonstrated that EpiCRAd was able to modulate the epigenome of cancer cells without affecting viruses’ infectivity. Upon examining the potential effect of EpiCRAd on cancer cells, we observed that epigenetic regulation did not notably influence the expression of MHC class I and PD- L1 proteins, both of which play a role in the immune evasion mechanism of tumour cells. In addition, the in vivo experiments show that EpiCRAd controls tumour growth the best, especially together with an immune checkpoint inhibitor, suggesting that the virus was able to create an immune microenvironment more favourable for anti-tumour response. Interestingly, the TAM infiltration in the TME seems to reduce after treatment with EpiCRAd. Overall, the combination of epigenetic therapy with oncolytic virotherapy has shown promising results in converting immunotherapy-resistant tumours into immunotherapy-responsive tumours. Our findings provide valuable insights into the effect of EpiCRAd on cancer and immune cells. This study encourages exploring the use of epigenetic cancer remodelling and oncolytic viruses for cancer immunotherapy.

Coronary heart disease is a number one killer in westernized countries and the costs from it will continue to grow in the future. It is caused by atherosclerosis, build-up of plaque and chronic inflammation in the arteries of heart, and endogenous lipoproteins have a special role in its development. Among other atheroprotective properties, High density lipoproteins (HDL) have a role in intrinsic mechanism of the reverse cholesterol transport (RCT), of gathering and removing excess cholesterol from peripheral tissues. There have been several HDL raising strategies in the past for the treatment of atherosclerosis, but their success has been modest. Synthetic HDL (sHDL), comprising of various types of phospholipids and proteins or peptides, have been developed to mimic the properties of endogenous HDL. Despite some success in animal studies, failures in clinical studies have turned the focus on the HDL’s interaction with a specific enzyme lecithin:cholesterol acyl transferase (LCAT), responsible for cholesterol esterification, a key step in RCT. ApoA-I, the most abundant protein component of HDL, acts as LCAT cofactor in cholesterol esterification, and many LCAT activating peptides have been developed to mimic the features of apoA-I. The molecular level understanding behind LCAT activation is however still foggy. During enzymatic activation, LCAT goes through conformational changes specific regions, which are generated by interactions with apoA-I or synthetic peptides. These mechanisms have been studied widely with molecular dynamic simulations, in vitro experiments, and imaging. In this study, we investigated 22A (PVLDLFRELLNELLEALKQKLK), apoA-I mimetic peptide known for its as good LCAT activation potency as apoA-I, and four variations of it (21A, 22A-P, 22A-K22Q, and 22A-R7Q), and combined them with phospholipid DPPC to create sHDL nanodiscs by thermal cycling method. We examined the effect of small changes in peptide sequence on LCAT-sHDL binding strength with quartz crystal microbalance with dissipation (QCM-D). The interest was to further test the suitability of thermal cycling method on nanodisc assembly, test the binding strengths against the hypothesis of the role of salt-bridge forming amino acids R7 and K22 in peptide dimerization and its effect on LCAT binding and activation, and to see if QCM could act as a suitable method for the research of sHDL-LCAT interactions. All peptides formed similar sized sHDL particles with diameter of ~10 nm with thermal cycling method. As expected, the LCAT binding tendency of 22A-sHDL was highest, about double compared to four other peptide nanodiscs with almost identical results. The QCM results suggest that binding tendency between LCAT and sHDL is affected by small, one amino acid change in peptide sequence, but it does not necessarily have a big impact on LCAT’s esterification activity, but based on this experiment alone, we cannot make any further conclusions. Electron microscopy revealed exceptional breakdown of 21A-sHDL incubated with LCAT compared to 22A-sHDL. This phenomenon could indicate high lipolytic rate of LCAT but needs further investigation. There were some challenges with the measurement parameters in the beginning, and the variability between parallel measurements with QCM-D was high, which cause a little doubt about the method’s suitability for these kinds of precise measurements. More research for revealing the molecular mechanism behind LCAT activation is needed for the development of more effective treatments.

P-glycoprotein (ABCB1, MDR1) is an efflux transporter expressed widely through the body, but mainly focused on tissues that have protective or excretive function, such as liver and blood-brain-barrier. Many clinically used drugs from variety of therapeutic groups are substrates of P-glycoprotein, and changes in the function of P-glycoprotein may have impact on the drugs pharmacokinetics and -dynamics. The impact of genetic polymorphism on P-glycoprotein activity have been investigated for several years, but due to contradictory results no consensus has been made. The aim of this Master’s thesis was to investigate the effect of five different P-glycoprotein single nucleotide polymorphisms (SNPs) on transport activity. The study was performed by Spodoptera frugiperda (Sf9) membrane vesicles expressing P-glycoprotein variants. Baculovirus-derived expression system was used to introduce the ABCB1 gene to the cells. Vesicle assay was performed with N-methylquinidine (NMQ), and ATP-dependent transport of P-glycoprotein variants was compared to the reference gene. Amino acid change Cys717Tyr led to no transport activity compared to reference gene, and Arg669Cys associated with higher transport activity of NMQ. Arg588Cys, Ser795Cys and Ile836Val indicated no effect on the transport activity. Other aim for this Master’s thesis was to create a new in-house protocol to study P-glycoprotein polymorphism in vitro. Substrate accumulation assay for Rhodamine-123 in Sf9 cells analysed with flow cytometry was established, as flow cytometry is widely used method in other laboratories to study P-glycoprotein polymorphism. The baseline for flow cytometry assay was created successfully by optimizing substrate concentration and incubation time. According to the results, SNPs can impair P-glycoprotein function. New method to study P-glycoprotein function was created, and this method can be used to further study the effects of genetic polymorphism of P-glycoprotein and to compare the result between studies. The results gained from these in vitro studies can be utilized to understand in vivo pharmacogenetic findings.

The ABCG2-protein is an ATP-dependent half transporter. It is found on apical membranes in intestine, liver, kidney, blood-brain barrier and placenta where it regulates absorption, distribution and elimination of many drugs, but also natural compounds and endogenous metabolites. Natural variation found on the ABCG2-gene can alter protein expression and transport activity. The altered function has been linked to pharmacokinetic changes and developing of diseases like gout. Studying natural ABCG2-variants and their effect gathers knowledge not only on their effect on pharmacokinetics but also on the ABCG2- transporters’ mechanism of function. The aim of this study was to combine an activating (I456V or H457R) and an inactivating (Q141K, F431L or T542A) non-synonymous single nucleotide variant in the same gene to study their combined effect on the ABCG2-transporter expression and active transport. Mutations were incorporated into the ABCG2- gene by site directed mutagenesis and the protein was expressed on HEK293-cells. The transport activity for Lucifer-Yellow and estrone sulfate was measured using HEK293-ABCG2-vesicles produced from cell membranes. The protein expression was measured with Western blot and mass spectrometry proteomics. Based on this study, different mutations together can alter each other’s effects, but the combined result is not always equal to the sum of variations. T542A-mutation did not show significant increase on the protein expression on any of the T542A-combinations, even though it has had such an effect in earlier studies. I456V, earlier expressed like wild type ABCG2, seemed to increase protein expression in all combinations. Q141K, F431L and T542A -mutations had lowering not expression dependent effect on the transport activity. F431L-mutation being so dominant that either of the two activating mutations could not restore the active transport in combinations. As seen before, H457R-variant seemed to cause a significant substrate specific activating effect on transport activity also in this study when combined with other mutations. However, H457R had a strong lowering effect on the protein expression and two of the combinations did not produce enough protein for active transport. As seen in this study, the ABCG2-doublemutations can cause altered ABCG2-function and lead to pharmacokinetic changes. These types of in vitro studies are important in studying these less common genetic variants which in lack of study subjects can be hard to study on clinical trials.

Liposomes are nano-sized vesicles, that are composed of a phospholipid bilayer structure. They can be utilized as drug carriers, in which case the drug is incorporated either to their hydrophilic internal cavity, or into their hydrophobic bilayer structure. For anticancer drugs, liposomal formulations have exhibited their capability in reducing adverse effects of anticancer drugs. This is achieved mainly by the enhanced permeability and retention (EPR) effect, in which liposomes accumulate into tumour tissue. However, the conventional liposomes release their drug content passively, and a proportion of drug is distributed to off-target tissues. Therefore, there is a demand to develop liposomes from which the content can be released in a controlled manner, by an external stimulus. The objectives of this master’s thesis project were to determine the potential of light-activated paclitaxel (PTX) liposomes for the treatment of lung cancer, and to optimize a dynamic cell culture system, QuasiVivo® (QV), to study the off-target effects of light-activated PTX liposomes. The hypothesis was that the induction of the light-activated PTX liposomes would increase the efficiency of paclitaxel treatment. For QV experiments, it was expected that the presence of flow would improve the viability of the cells. The encapsulation efficiency of PTX into the liposomes and the effect of the PTX incorporation into the phase transition temperature of the liposomes were determined. The stability of liposomes was determined by monitoring the liposomal size and light sensitizer absorbance during a storage period. The cells of lung cancer cell line A549 were cultured inside QV system, and their viability was monitored with two commercial cell viability assays. Incorporation of PTX decreased the phase transition temperature, but the liposomes remained stable in the studied conditions. The PTX liposome treatments with and without light activation resulted in the similar efficacy as free PTX treatment did. A549 cells failed to display superior viability inside the QV compared to static conditions. Cells cultured under lower flow rate portrayed modestly higher viability. The light-activated PTX liposomes did not improve the efficacy of PTX treatment. Neither of the flow rates were optimal for A549 cells, as the variation between experiments was high. The EPR effect is the main reason for the improved effects of liposomal anticancer drugs, therefore, it is likely that in vivo experiments would elicit the differences between the efficacy of the liposomal and free PTX. The non-existent effects of light activation on the viability are likely caused by the low total concentration of the light sensitizer in the treatment solution.

Statins are a commonly used group of drugs that reduce the cholesterol levels in blood and have been shown to reduce cardiovascular morbidity and mortality. However, a considerable percentage of patients experience adverse effects during statin treatment. Statin adverse effects have been associated with genetic polymorphisms and drug-drug interactions that affect the elimination and active transport of these drugs. A more comprehensive knowledge of statin metabolism may be a step towards better management of statin treatments. Statin metabolism both in vivo and in vitro has been subject of study for years. In vitro incubation conditions may considerably affect the observed clearance, and results obtained with different methods or in different laboratories may not be directly comparable to each other. No single in vitro study on a wide panel of statins has previously been conducted. Six statins and some of their metabolites, fourteen compounds in total, were included in the study. The intrinsic clearance (CLint) of these molecules was investigated in vitro on human liver microsomes (HLM) and a panel of eleven cytochrome P450 (CYP) enzymes recombinantly expressed in E. coli. Observed CLint values for each compound in HLM and for each compound-CYP pair with observed depletion were calculated. The percentual contributions of each CYP enzyme to the metabolism of the compounds was calculated. The results obtained with recombinant CYP enzymes (rcCYP) were complemented with studies on HLM with specific chemical inhibitors of CYP enzymes. In this study the metabolism of statin lactones seemed to be faster than the metabolism of the corresponding statin acids. Atorvastatin lactone, 2-hydroxy atorvastatin lactone, 4-hydroxy atorvastatin lactone and simvastatin were extensively metabolized. Atorvastatin, 2-hydroxy atorvastatin, 3R,5S-fluvastatin, 3S,5R-fluvastatin, pitavastatin lactone and simvastatin acid showed intermediate metabolism. 4-hydroxy atorvastatin, pitavastatin, pravastatin and rosuvastatin rates of metabolism were below quantification limit. CYP3A4 had a major role in the metabolism of atorvastatin and its metabolites, simvastatin and simvastatin acid. CYP3A4 also had activity towards pitavastatin lactone. CYP2C9 had a high activity towards both 3R,5S-fluvastatin and 3S,5R-fluvastatin. CYP2D6 may play a part in the metabolism of pitavastatin lactone. CYP2C8 may have some activity towards simvastatin and simvastatin acid. The data is mostly in agreement with previous in vitro and in vivo studies regarding both the metabolism rate of statins and the contributions by different CYP enzymes to the metabolism of statins. Due to the screening nature of the study and some methodological constraints, these data should be considered as preliminary and require confirmation in further studies.