| 1. |
- Abouzayed, Ayman, 1992-
(författare)
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Theranostic Targeting of GRPR and PSMA in Prostate Cancer
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is based on five original articles that investigated the theranostics of prostate cancer by gastrin-releasing peptide receptor (GRPR) and prostate-specific membrane antigen (PSMA) targeting. GRPR and PSMA are two extensively evaluated prostate cancer cell markers due to their overexpression in the majority of prostate cancer samples. Theranostic targeting of GRPR and PSMA is an attractive strategy to improve the management of prostate cancer patients.Papers I and II focused on the dual targeting of GRPR and PSMA. The effect of linker modification on the affinity for GRPR and PSMA and the pharmacokinetic profile was evaluated. In Paper III, the effect of the GRPR antagonist RM26 conjugation to an albumin-binding domain on the pharmacokinetic profile and its potential use in therapy was investigated. Paper IV focused on developing a GRPR antagonist that was suitable for single-photon emission computed tomography (SPECT) using technetium-99m. In Paper V, the GRPR antagonist developed in Paper IV was translated into a phase I clinical trial to assess safety and dosimetry.Modifying the linkers in GRPR and PSMA heterodimers can largely impact the affinity for both targets. This modification influenced the in vivo targeting specificity and biodistribution, with [125I]I-BO530 in Paper I and [111In]In-BQ7812 in Paper II outperforming other analogues. Our findings in Paper III indicated that the conjugation of an albumin-binding domain to RM26 increased the blood concentration of the radiotracer. This increase led to elevated and stable tumour uptake of [111In]In-DOTA-ABD-RM26 after several days of injection. However, [111In]In-DOTA-ABD-RM26 was also increasingly taken up by various healthy organs. The GRPR antagonist [99mTc]Tc-maSSS-PEG2-RM26, studied in Paper IV, showed high specificity and affinity for GRPR. This resulted in elevated GRPR-mediated uptake. Additionally, maSSS-PEG2-RM26 could be radiolabelled via a straightforward radiolabelling protocol. Clinical evaluation of [99mTc]Tc-maSSS-PEG2-RM26 in prostate and breast cancer patients (Paper V) demonstrated the safety and tolerability of the radiotracer, with favourable dosimetry and no side effects.In conclusion, this thesis evaluated different tools for the theranostic targeting of GRPR and PSMA. The findings warrant further investigation to optimise the reported radiotracers.
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| 2. |
- Adeyemi, Ahmed, 1986-
(författare)
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Palladium(0)-Catalyzed Synthesis of Spirocycles and Supercritical Chemistry using a Resistively Heated Flow Reactor
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This doctoral thesis focusses on an effective and selective approach to the synthesis of spirocycles using palladium(0)-catalyzed Mizoroki-Heck reactions. In addition, selective and efficient chemistry was highlighted by the design and evaluation of a novel resistively heated system for continuous flow (CF) synthesis for high-temperature and high-pressure applications.Paper I described the design and evaluation of a novel resistively heated CF system. The design of a low-cost, simple, robust, and effective CF system involving a resistively heated steel reactor capable of delivering 400 °C and 200 bar was reported. The reactor was evaluated with esterification, transesterification and direct carboxylic acid to nitrile conversions using supercritical ethanol, methanol and acetonitrile respectively. Diels-Alder reactions under neat conditions were also carried out at high temperature and pressure.Paper II reported the synthesis of spirooxindoles by a selective application of the palladium(0)-catalyzed Mizoroki-Heck spirocyclization. The precursors for the reaction were synthesized by coupling 2-iodoanilines with esters derived from enantiomerically pure (+)-Vince lactam decorated with the bulky, directing 2,5-dimethylpyrrole protecting group. Ten different spirooxindoles were reported with good yields and high regio- and stereoselectivity. Functionalization of a synthesized spirooxindole was done by a palladium(0)-catalyzed alkoxycarbonylation, followed by selective deprotections.In Paper III, ether precursors were synthesized from (+)-Vince lactam, via a Mitsunobu reaction with the corresponding iodophenols. The precursors were later subjected to conditions for intramolecular Mizoroki-Heck reaction. Overall, 12 spiroethers were synthesized in useable yields, regioselectivity up to 98% and with excellent diastereoselectivity (d.e.>98%). Further functionalization to mono-protected rigidified amino acids was also demonstrated.
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| 3. |
- Aerts, Jordan
(författare)
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Capillary electrophoresis mass spectrometry applied to structural proteomics and small molecule analysis
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Capillary electrophoresis with mass spectrometric (CE–MS) detection offers a separation method without equal in terms of flexibility, utility, and cost efficiency. Here we demonstrate precisely this through the application of several laboratory-built CE–MS instruments for the separation of brain metabolites in non-primates, enantioselective separations of synthetic anesthetic metabolites in fractionated pony urine, application in structural proteomics workflows, and identification of exogenous alkaloid biotransformationproducts in human cerebrospinal fluid (CSF).We outline a method for quickly and affordably etching austenitic steel tubing, which is widely used in electrospray sources for CE–MS. The stainless steel tapered tip emitters provide robust electrospray with low sheath liquid flow rates and can be easily fabricated in-house, offering flexibility and cost-efficiency when commercial options areunavailable. We contribute a CE–MS method for enantiomer separation, specifically targeting 6-hydroxynorketamine (HNK). By introducing chiral selectors into the separation capillary, the method enables efficient enantiomer separation and offers a newtool to assist with research on HNK as a cure for depression.We explore the feasibility of cold CE–MS in hydrogen deuterium exchange workflows. The utilization of a lab-designed Peltier-cooled CE device achieves deuterium back exchange rates on par with commercial liquid chromatography-based platforms, offering new possibilities for studying protein structures and interactions.We also demonstrate the wide ranging versatility of CE–MS with contributions to the identification of specific tobacco related metabolites in CSF samples during the development of a high throughput mass spectrometry diagnostic tool for Parkinson’sDisease.This thesis showcases the versatility and value of CE–MS in various applications, a true blessing for analytical chemistry.
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| 4. |
- Al-Tikriti, Yassir
(författare)
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Microgels as drug delivery vehicles : loading and release of amphiphilic drugs
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Polyelectrolyte microgels are used as delivery vehicles for amphiphilic drugs in, e.g., treatments of liver cancer by a method called trans-arterial chemoembolization. The thesis deals with fundamental properties of such delivery systems related to the self-assembling properties of the drug molecules and their interaction with the charged polymer network of the microgel. The main objective was to establish mechanistic models describing the loading and release of drugs under relevant conditions. For that purpose experimental techniques providing thermodynamic, compositional and microstructural information were used to elucidate how the kinetics depend on the stability of the drug self-assemblies and the volume response of the microgels. Micromanipulator-assisted microscopy studies showed that negatively charged microgels phase separated during loading and release of cationic amphiphilic drugs. At intermediate loading levels the drug aggregates and part of the network formed a collapsed phase coexisting with a swollen, drug-lean phase. In particular, during release in a medium of physiological ionic strength, the drug-lean phase formed a depletion layer (shell) surrounding a drug-rich core. Investigations of a series of drugs with different molecular architectures showed that the drug release rate was determined mainly by the stability of the drug aggregates in the core and the diffusive mass transport of drug molecules through the shell. Detailed studies of polyacrylate microgels interacting with amitriptyline hydrochloride showed that swelling of the shell network greatly influenced the release rate. Furthermore, experiments with a specially constructed microscopy cell was used to establish that the collapsed and swollen phases could coexist in equilibrium, and that the swelling of the network in the swollen phase depended on the proportion between them when present in the same microgel. The latter effect was related to the elastic coupling between the phases. Confocal Raman microscopy was employed to demonstrate, for the first time, the related elastic effect, that the concentration of amitriptyline in the swollen phase decreased with increasing proportion of the collapsed phase. Small-angle X-ray scattering showed that the collapsed phase had a disordered microstructure of drug micelles with ellipsoidal shape. The aggregation number increased with increasing concentration of drug in the microgel, most likely by incorporating the uncharged base form. By providing detailed information about thermodynamic properties and microstructures, the results of the thesis provide a basis for rational design of microgel drug delivery systems.
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| 5. |
- Alvebratt, Caroline
(författare)
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Advanced Methods for Evaluation of the Performance of Complex Drug Delivery System
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Low oral bioavailability of drugs originating from poor aqueous solubility is a common issue in drug development. Various enabling formulations have been presented to circumvent this limitation, many making use of supersaturation. In these, the drug is delivered to the gastro-intestinal lumen in a high energy state e.g. in amorphous form or a liquid lipid vehicle. Concentrations surpassing the equilibrium solubility of the crystalline drug are achieved, which facilitate increased absorption for dissolution-rate limited compounds. Meanwhile the use of the enabling formulation can be beneficial to increase the bioavailability of poorly water-soluble drugs, in vitro evaluation of these systems remain challenging. Limited methods have also evaluated several different types of enabling formulation in the same experimental setup. The overall aim of this thesis was therefore to develop assays to study the performance of various complex drug delivery systems. In the first part, a small scale dissolution apparatus, the µDiss Profiler, was used to study drug release from drug-loaded mesoporous magnesium carbonate (MMC). A protective filter was developed to minimize particle interference on the UV-measurements, enabling studies of supersaturation from the amorphous carrier. In the second paper, lipids were adsorbed onto the MMC. A modified in vitro lipolysis setup was established and the samples were analyzed with nuclear magnetic resonance spectroscopy. A stability study of the lipid-loaded MMC was also performed. The methods developed in the first two projects provided an insight to events occurring in the intestinal lumen. The intestinal absorption has however been shown to be a complex interplay between dissolution-digestion and permeation. In the final two projects, two devices comprising of a donor (luminal) chamber and a receiver (serosal) chamber were studied (the µFLUX and the enabling absorption, ENA, device). The two chambers were separated by a semipermeable membrane (cell-based and/or phospholipid-based). A wide range of enabling formulations were evaluated in the two assays. As the exposure in the donor correlated poorly with the exposure in the receiver compartment, this emphasizes the importance of in vitro methods taking both the dissolution-digestion and permeation into account. The ENA results also predicted the in vivo performance in rats well. To conclude, several models have been established in the thesis to study the in vitro performance of enabling formulations, which will be valuable for screening of appropriate drug delivery systems.
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| 6. |
- Andersson, Sara B. E., 1987-
(författare)
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Novel and refined small-scale approaches to determine the intrinsic dissolution rate of drugs
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Many drugs are administered as crystalline particles compressed into tablets and taken orally. When the tablet reaches the gastrointestinal tract, it disintegrates and the drug particles dissolve in the gastrointestinal fluid. The dissolved molecules are absorbed across the intestinal membranes into the bloodstream to reach their target sites. Only dissolved molecules can be absorbed, and if a drug has low solubility and/or dissolution rate in gastrointestinal fluid, the drug absorption might be insufficient. Hence, knowing the solubility and dissolution behaviour of a potential drug candidate is necessary early in the drug development process. The aim of this thesis was to evaluate and refine different approaches for measuring and determining dissolution rate, as well as to develop novel in vitro small-scale dissolution methods. First, interlaboratory variability in determination of intrinsic dissolution rate (IDR) and apparent solubility (Sapp) was investigated using a miniaturized dissolution instrument. To minimize the interlaboratory variability, standardized protocols for both the experimental design and the data analyses were required, and a flow chart for performing standardized powder and disc IDR measurements was established. Next, as an alternative to the powder and disc methods, carefully dispersed suspensions were used to determine the IDR, and rapid and more controlled IDR measurements were obtained using suspensions with dispersed primary particles. From the suspension measurements, an IDR/Sapp ratio of the compounds were determined. This ratio can potentially be used to identify whether a compound is likely to show dissolution rate-limited absorption and hence is sensitive to particle size reduction. The final experiments used a single particle dissolution approach to determine the IDR at four different fluid velocities. Computational fluid dynamics (CFD) simulations were used to theoretically investigate the flow conditions and dissolution rates. Single particle dissolution measurements under well-defined conditions gave high-quality dissolution data. An IDR was determined within 5-60 minutes using particles with initial diameters of 37.5-104.6 μm. The single particle dissolution experiments were used to determine the thickness of the effective hydrodynamic boundary layer (heff). The heff values were also assessed by CFD simulations, and a good concordance between experimental and simulated heff values was obtained. The approaches presented in this thesis can be used to derive qualified knowledge about the dissolution properties of drugs with several potential applications in drug development, such as profiling of solid drugs, informed formulation decisions, assisting the modelling of drug dissolution and providing improved understanding of the in vivo-dissolution behaviour
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| 7. |
- Ansari, Shaquib Rahman, 1993-
(författare)
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From design to application: Iron oxide nanoparticles for imaging and therapeutics in inflammatory and infectious diseases
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Superparamagnetic iron oxide nanoparticles (SPIONs) are a promising advancement in nanomedicine, demonstrating remarkable potential in both diagnostic and therapeutic applications. They can be magnetized in a magnetic field and do not show permanent magnetization, allowing precise localization within the body. Under an alternating magnetic field, SPIONs generate heat, which can be used for magnetic hyperthermia therapy against cancer or to trigger drug release. Diagnostically, they are widely used as contrast agents for magnetic resonance imaging (MRI), while magnetic particle imaging (MPI) is an emerging preclinical diagnostic technique using SPIONs as tracers.Despite these promising applications, the clinical utility of SPIONs is hindered by challenges related to scalable and reproducible manufacturing. Focused efforts are also needed to improve MPI resolution. Moreover, the application of magnetic hyperthermia for treating inflammatory and infectious conditions remains relatively underexplored. Therefore, the primary objective of this thesis was to develop SPIONs tailored for imaging and therapy of inflammatory and infectious diseases through scalable manufacturing techniques. The first part of the study involved a systematic review to examine the most pertinent research on use of SPIONs for diagnosing and treating chronic inflammatory diseases. MRI was identified as the predominant application of SPIONs. However, there was limited exploration of MPI and magnetic hyperthermia for imaging and treating inflammatory diseases, respectively.In the second project, a risk-based pharmaceutical quality by design approach was used to optimize SPIONs for magnetic hyperthermia. The effect of nanoparticle properties on MPI performance was systematically investigated in the third project. Additionally, these projects established flame spray pyrolysis as a scalable and reproducible technique, for synthesizing nanoparticles with complex stoichiometry for magnetic hyperthermia and MPI.In final part of the study, SPIONs were incorporated into composites by scalable techniques, to improve the treatment of inflammatory and infectious diseases. SPIONs were incorporated in tablets with an anti-inflammatory drug, celecoxib. The drug solubility improved significantly through magnetic hyperthermia-induced in situ amorphization. SPIONs were also incorporated into microfibers, and heat dissipation from magnetic microfibers was used with doxycycline against methicillin-resistant Staphylococcus aureus. This resulted in substantial reduction in bacterial growth compared to using the drug alone.This thesis introduced systematic exploration of SPION properties and their functional performance, established a scalable synthesis technique for their production, and developed novel systems for wider adaptation of SPIONs in biomedical applications.
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| 8. |
- Arvidsson McShane, Staffan, 1990-
(författare)
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Confidence Predictions in Pharmaceutical Sciences
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main focus of this thesis has been on Quantitative Structure Activity Relationship (QSAR) modeling using methods producing valid measures of uncertainty. The goal of QSAR is to prospectively predict the outcome from assays, such as ADMET (Absorption, Distribution, Metabolism, Excretion), toxicity and on- and off-target interactions, for novel compounds. QSAR modeling offers an appealing alternative to laboratory work, which is both costly and time-consuming, and can be applied earlier in the development process as candidate drugs can be tested in silico without requiring to synthesize them first. A common theme across the presented papers is the application of conformal and probabilistic prediction models, which are used in order to associate predictions with a level of their reliability – a desirable property that is essential in the stage of decision making. In Paper I we studied approaches on how to utilize biological assay data from legacy systems, in order to improve predictive models. This is otherwise problematic since mixing data from separate systems will cause issues for most machine learning algorithms. We demonstrated that old data could be used to augment the proper training set of a conformal predictor to yield more efficient predictions while preserving model calibration. In Paper II we studied a new approach of predicting metabolic transformations of small molecules based on transformations encoded in SMIRKS format. In this work use used the probabilistic Cross-Venn-ABERS predictor which overall worked well, but had difficulty in modeling the minority class of imbalanced datasets. In Paper III we studied metabolomics data from patients diagnosed with Multiple Sclerosis and found a set of 15 discriminatory metabolites that could be used to classify patients from a validation cohort into one of two sub types of the disease with high accuracy. We further demonstrated that conformal prediction could be useful for tracking the progression of the disease for individual patients, which we exemplified using data from a clinical trial. In Paper IV we introduced CPSign – a software for cheminformatics modeling using conformal and probabilistic methods. CPSign was compared against other regularly used methods for this task, using 32 benchmark datasets, demonstrating that CPSign produces predictive accuracy on par with the best performing methods.
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| 9. |
- Ayoun Alsoud, Rami, 1992-
(författare)
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Pharmacometric tools to support translational drug development
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The use of model-informed drug development has been shown to save significant costs and improve decision making early in the drug development process. The work in this PhD thesis aimed to employ pharmacometric tools to support translational drug development from the preclinical to the late clinical stages.Pharmacometric modeling was used to characterize the treatment-shortening potential of different anti tuberculosis regimens. The results provided additional evidence in favor of the treatment-shortening capacity of the BPaMZ regimen over BPaL and standard of care, HRZE.Pharmacokinetic-pharmacodynamic (PKPD) modeling was used to enable the evaluation of the exposure-response of a new anti-tubercular drug, MPL-447, in C3HeB/FeJ mice, thought to be of a translational value in tuberculosis drug development. Model-based evaluation revealed a significant impact of necrotic lesion development in mice on both bacterial growth and sensitivity to treatment with MPL-447, highlighting the significance of accounting for the heterogenous lesion profile in the C3HeB/FeJ mouse model when evaluating drug efficacy.Pharmacokinetic (PK) modeling was employed to perform interspecies PK scaling of the CB 4332 protein using information from three preclinical species. This approach accounted for the impact of immunogenicity and species-related differences in elimination. Simulations predicted the protein plasma concentrations in humans after different dosing regimens and suggested that a 7 mg/kg dose would be required to reach the target at steady-state.Using combined biomarker data, PKPD modeling was employed to simultaneously analyze two tuberculosis efficacy biomarkers. The final biomarker model facilitated the prediction of the relationship between the two biomarkers over time. With this modeling framework, missing biomarker data can be predicted using information from the other biomarker.Several model-based approaches were also explored to evaluate pediatric study power in rare diseases. These approaches were performed analyzing pediatric data alone or combined with the adult data. While Bayesian priors performed well when analyzing pediatric data alone, less technical modeling approaches proved sufficient when pediatric and adult data were combined.In conclusion, the research presented in this thesis has addressed various challenges encountered in translational drug development. The work has contributed to the evaluation of new anti-tubercular drugs and regimens, the assessment of newly proposed animal models, and optimizing the utilization of biomarker information. Furthermore, this thesis has provided insights into the selection of First-in-Human dose for a protein, showcasing the applicability of model-based approaches in this critical decision-making process. The research has contributed to improving analysis approaches for pediatrics in rare diseases.
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| 10. |
- Barmpatsalou, Vicky
(författare)
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Understanding the gastrointestinal mucus and its impact on drug absorption
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The gastrointestinal mucus is a hydrogel lining the luminal side of the gastrointestinal epithelium. Mucus is vital for gut homeostasis because it protects the epithelium from the noxious external environment. However, from a drug delivery perspective, drugs have to permeate through the mucus to reach the epithelium; therefore, mucus might pose a barrier to drug absorption. Most of the information about mucus derives from fundamental studies performed on rodents. However, information from larger preclinical animal species is highly warranted for improving study designs and guiding better interpretation of data from preclinical assessments. Furthermore, improved understanding of the nature of the gastrointestinal mucus would enable the development of in vitro mucus models with increased biorelevance. These could then be implemented in drug absorption assays to improve the (bio)predictability. Well-informed in vitro mucus models would enable quick and less variable screening of drug candidates in the early drug development stages. Finally, these models would contribute to reduction, refinement, and replacement (the 3Rs) of animal usage in the drug development process. This thesis aims to improve our understanding of the nature of gastrointestinal mucus and its impact on drug absorption. For this purpose, mucus from the complete gastrointestinal tract of pigs and dogs was characterized and the diffusion of physicochemically diverse FITC-dextrans through colonic mucus was studied, both ex vivo and in vitro. The characterization of the gastrointestinal mucus focused on properties relevant for drug absorption and revealed the physiological characteristics, composition, and structural profiles from the various gastrointestinal regions. The findings pointed towards substantial differences between small intestinal and colonic mucus in both species and served as the basis for developing artificial colonic mucus models for drug permeation assessments. Porcine and canine artificial mucus models were developed and validated against the respective native secretions in terms of structural properties and demonstrated their potential to capture the key diffusion patterns of FITC-dextrans observed in native colonic mucus. Overall, this work provided insights into key properties of mucus from large preclinical species and validated tools for the assessment of the impact of mucus on drug absorption.
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