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| 2. |
- Ahnfelt, Emelie, et al.
(author)
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Lipiodol-based emulsions used for transarterial chemoembolization and drug delivery : Effects of composition on stability and product quality
- 2019
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In: Journal of Drug Delivery Science and Technology. - : ELSEVIER. - 1773-2247. ; 53
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Journal article (peer-reviewed)abstract
- Transarterial chemoembolization with emulsion-based formulations using doxorubicin hydrochloride (DOX) and Lipiodol (R) is the golden standard for the loco-regional treatment of unresectable hepatocellular carcinoma (HCC). However, from a pharmaceutical quality perspective these emulsions are poorly characterized. In this study, clinically relevant Lipiodol (R)-based emulsions were characterized in terms of emulsion stability, continuous phase classification and droplet-size distribution. Also, the solubility of DOX in the different emulsion components and the distribution of DOX to the lipid phase were investigated. These are key features to investigate due to the claimed tumor-seeking properties of Lipiodol (R). The in vitro release of DOX was studied in a miniaturized dialysis method and an empirical release model was applied to adjust for the passage of DOX across the dialysis membrane. The most stable emulsion ( > 72 h) was classified as water-in-oil (w/o), had the highest distribution of DOX to the lipid phase (20%) and an aqueous-to-lipid phase ratio of 1:4. The composition of the aqueous phase was a mixture (v/v) of iohexol (85%) and water (15%). Emulsions containing iohexol and a high aqueousto-lipid phase ratio (1:2-1:4) displayed prolonged in vitro release profiles of DOX. This study further emphasizes the medical need to standardize these emulsion-based drug delivery systems.
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| 3. |
- Calitz, Carlemi, et al.
(author)
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Influence of extracellular matrix composition on tumour cell behaviour in a biomimetic in vitro model for hepatocellular carcinoma
- 2023
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In: Scientific Reports. - : NATURE PORTFOLIO. - 2045-2322. ; 13:1
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Journal article (peer-reviewed)abstract
- The tumor micro-environment (TME) of hepatocellular carcinoma (HCC) consists out of cirrhotic liver tissue and is characterized by an extensive deposition of extracellular matrix proteins (ECM). The evolution from a reversible fibrotic state to end-stage of liver disease, namely cirrhosis, is characterized by an increased deposition of ECM, as well as changes in the exact ECM composition, which both contribute to an increased liver stiffness and can alter tumor phenotype. The goal of this study was to assess how changes in matrix composition and stiffness influence tumor behavior. HCC-cell lines were grown in a biomimetic hydrogel model resembling the stiffness and composition of a fibrotic or cirrhotic liver. When HCC-cells were grown in a matrix resembling a cirrhotic liver, they increased proliferation and protein content, compared to those grown in a fibrotic environment. Tumour nodules spontaneously formed outside the gels, which appeared earlier in cirrhotic conditions and were significantly larger compared to those found outside fibrotic gels. These tumor nodules had an increased expression of markers related to epithelial-to-mesenchymal transition (EMT), when comparing cirrhotic to fibrotic gels. HCC-cells grown in cirrhotic gels were also more resistant to doxorubicin compared with those grown in fibrotic gels or in 2D. Therefore, altering ECM composition affects tumor behavior, for instance by increasing pro-metastatic potential, inducing EMT and reducing response to chemotherapy.
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| 4. |
- Degerstedt, Oliver, et al.
(author)
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Drug diffusion in biomimetic hydrogels : importance for drug transport and delivery in non-vascular tumor tissue
- 2022
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In: European Journal of Pharmaceutical Sciences. - : Elsevier. - 0928-0987 .- 1879-0720. ; 172
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Journal article (peer-reviewed)abstract
- Hydrogels of varying complexity are routinely used as scaffolds and 3D structures for in vitro tumor models to increase physiological relevance within pre-clinical cancer research. Relatively simple hydrogels such as agarose are well characterised, meanwhile biomimetic gels containing collagen and fibrin(ogen) have been studied to a much lesser extent. In this study, hydrogels mimicking the biophysical characteristics of liver cancer progression were investigated in terms of their UV-properties and influence on diffusion coefficients of different substances. UV-imaging technology was used to both visualize and quantify the diffusion process in a simple and rapid way. In general, agarose gel diffusion agreed well with predictions using the Stokes-Einstein equation meanwhile the biomimetic gels reduced diffusion coefficients by up to 70%. For doxorubicin, spatio-temporal tissue concentration modelling was used to translate in vitro diffusion to the more clinical context of tumor penetration in a solid liver tumor supplied by arterial blood.
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| 5. |
- Degerstedt, Oliver, et al.
(author)
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Quantitative imaging of doxorubicin diffusion and cellular uptake in biomimetic gels with human liver tumor cells
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Other publication (other academic/artistic)abstract
- Novel tumor-on-a-chip approaches are increasingly used to investigate tumor progression and potential treatment options. To improve the effect of any cancer treatment it is important to have an in-depth understanding of drug diffusion, penetration across the tumor extracellular matrix and cellular uptake. In this study, we have developed a miniaturized chip where drug diffusion and cellular uptake in different hydrogel environments can be quantified at high resolution using live imaging. Diffusion of doxorubicin was reduced in a biomimetic hydrogel mimicking tissue properties of cirrhotic liver and early stage hepatocellular carcinoma (362 ± 109 µm2/s) as compared to an agarose gel (571 ± 145 µm2/s, p = 0.0085). The diffusion was further lowered to 164 ± 33 µm2/s (p = 0.0023) by preparing the biomimetic gel in cell media instead of phosphate buffered saline. The addition of liver tumor cells (Huh7 or HepG2) to the gel, at two different densities, did not significantly influence drug diffusion. Clinically relevant and quantifiable doxorubicin concentration gradients (1-20 µM) were established in the chip within one hour. Intracellular increases in doxorubicin fluorescence correlated with decreasing fluorescence of the DNA-binding stain Hoechst 33342, and based on the quantified intracellular uptake of doxorubicin an apparent cell permeability (9.00 ± 0.74 x 10-4 µm/s for HepG2) was determined.
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| 6. |
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| 7. |
- Degerstedt, Oliver
(author)
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Translational Tumor Drug Delivery : Doxorubicin formulation performance, intracellular uptake and molecular diffusion
- 2023
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Doctoral thesis (other academic/artistic)abstract
- Globally, hepatocellular carcinoma (HCC) is the most common form of liver cancer and a leading cause of cancer death. One important risk factor is liver cirrhosis and the disease progression is characterized by deposition of extracellular matrix proteins that form a fibrous network, which increases liver stiffness and may limit the effectiveness of different treatment strategies. The overall aim of this thesis was to investigate the anticancer drug doxorubicin (DOX) and its clinically relevant drug delivery systems from an in vitro perspective. The focus was on developing and using qualitative and quantitative methods to better understand formulation performance, intracellular uptake and molecular diffusion. The experimental in vitro findings were then translated to clinical scenarios using physiologically based pharmacokinetic (PBPK) modelling.The performance of clinically employed emulsion formulations containing DOX and the tumor accumulating oil Lipiodol® were evaluated in terms of their stability (Paper I). The most stable emulsion (> 72 h) was achieved when using an aqueous phase containing the contrast agent iohexol and with an aqueous to lipid phase ratio of 1:4 to assure formation of a water-in-oil emulsion. This was followed by a cell-based study (Paper II) where nanoformulated DOX was compared to DOX in solution in terms of tumor cell toxicity, intracellular DOX uptake and intracellular formation of the main active metabolite doxorubicinol (DOXol). DOX in solution was more potent in all investigated cell lines, where the most sensitive cells (HepG2) displayed IC50 values that were approximately 100 times lower than the most resistant cell line (SNU449). This was explained by the rapid intracellular uptake in HepG2 cells which was also confirmed with a complimentary miniaturized chip technique in Paper IV. In papers III and IV the focus was on molecular diffusion across biomimetic hydrogels mimicking tissue properties of cirrhotic liver and early stage HCC. The diffusion of DOX was significantly reduced in biomimetic gels as compared with more commonly used agarose gels, however the presence of human liver tumor cells did not significantly influence diffusion. Simulations using a developed PBPK and spatio-temporal tissue concentration model suggested that a liver tumor resembling SNU449 cells would not reach therapeutic exposure levels in a clinical scenario while the diffusion of DOX required further reduction by the tumor extracellular matrix in order to generate tumor concentration-time curves consistent with in vivo observations.This thesis contributes to an increased understanding of using DOX and its drug delivery systems as a treatment option for HCC. The approach of translating in vitro experimental data to clinical scenarios using modelling will grow in relevance as methods become more complex and data more bio-relevant.
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| 8. |
- Kullenberg, Fredrik, et al.
(author)
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In Vitro Cell Toxicity and Intracellular Uptake of Doxorubicin Exposed as a Solution or Liposomes : Implications for Treatment of Hepatocellular Carcinoma
- 2021
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In: Cells. - : MDPI. - 2073-4409. ; 10:7
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Journal article (peer-reviewed)abstract
- Cytostatic effects of doxorubicin in clinically applied doses are often inadequate and limited by systemic toxicity. The main objective of this in vitro study was to determine the anti-tumoral effect (IC50) and intracellular accumulation of free and liposomal doxorubicin (DOX) in four human cancer cell lines (HepG2, Huh7, SNU449 and MCF7). The results of this study showed a correlation between longer DOX exposure time and lower IC50 values, which can be attributed to an increased cellular uptake and intracellular exposure of DOX, ultimately leading to cell death. We found that the total intracellular concentrations of DOX were a median value of 230 times higher than the exposure concentrations after exposure to free DOX. The intracellular uptake of DOX from solution was at least 10 times higher than from liposomal formulation. A physiologically based pharmacokinetic model was developed to translate these novel quantitative findings to a clinical context and to simulate clinically relevant drug concentration-time curves. This showed that a liver tumor resembling the liver cancer cell line SNU449, the most resistant cell line in this study, would not reach therapeutic exposure at a standard clinical parenteral dose of doxorubicin (50 mg/m(2)), which is serious limitation for this drug. This study emphasizes the importance of in-vitro to in-vivo translations in the assessment of clinical consequence of experimental findings.
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| 9. |
- Kullenberg, Fredrik, et al.
(author)
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The progression of doxorubicin-induced intestinal mucositis in rats
- 2023
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In: Naunyn-Schmiedeberg's Archives of Pharmacology. - : Springer Nature. - 0028-1298 .- 1432-1912. ; 396, s. 247-260
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Journal article (peer-reviewed)abstract
- Chemotherapy-induced intestinal mucositis is a severe side effect contributing to reduced quality of life and premature death in cancer patients. Despite a high incidence, a thorough mechanistic understanding of its pathophysiology and effective supportive therapies are lacking. The main objective of this rat study was to determine how 10 mg/kg doxorubicin, a common chemotherapeutic, affected jejunal function and morphology over time (6, 24, 72, or 168 h). The secondary objective was to determine if the type of dosing administration (intraperitoneal or intravenous) affected the severity of mucositis or plasma exposure of the doxorubicin. Morphology, proliferation and apoptosis, and jejunal permeability of mannitol were examined using histology, immunohistochemistry, and single-pass intestinal perfusion, respectively. Villus height was reduced by 40% after 72 h, preceded at 24 h by a 75% decrease in proliferation and a sixfold increase in apoptosis. Villus height recovered completely after 168 h. Mucosal permeability of mannitol decreased after 6, 24, and 168 h. There were no differences in intestinal injury or plasma exposure after intraperitoneal or intravenous doxorubicin dosing. This study provides an insight into the progression of chemotherapy-induced intestinal mucositis and associated cellular mucosal processes. Knowledge from this in vivo rat model can facilitate development of preventive and supportive therapies for cancer patients.
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