| 1. |
- Johansson, Veronica, et al.
(författare)
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Effect of polyamine deficiency on proteins involved in Okazaki fragment maturation.
- 2008
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Ingår i: Cell Biology International. - : Wiley. - 1095-8355 .- 1065-6995. ; 32, s. 1467-1477
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Tidskriftsartikel (refereegranskat)abstract
- Polyamine depletion causes S phase prolongation, and earlier studies indicate that the elongation step of DNA replication is affected. This led us to investigate the effects of polyamine depletion on enzymes crucial for Okazaki fragment maturation in the two breast cancer cell lines MCF-7 and L56Br-C1. In MCF-7 cells, treatment with N(1),N(11)-diethylnorspermine (DENSPM) causes S phase prolongation. In L56Br-C1 cells the prolongation is followed by massive apoptosis. In the present study we show that L56Br-C1 cells have substantially lower basal expressions of two Okazaki fragment maturation key proteins, DNA ligase I and FEN1, than MCF-7 cells. Thus, these two proteins might be promising markers for prediction of polyamine depletion sensitivity, something that can be useful for cancer treatment with polyamine analogues. DENSPM treatment affects the cellular distribution of FEN1 in L56Br-C1 cells, but not in MCF-7 cells, implying that FEN1 is affected by or involved in DENSPM-induced apoptosis.
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| 2. |
- Mcgowan, Asmaa, et al.
(författare)
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Injectable Biodegradable Silica Depot for Controlled Subcutaneous Delivery of Antisense Oligonucleotides with beyond Monthly Administration
- 2023
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Ingår i: Molecular Pharmaceutics. - : AMER CHEMICAL SOC. - 1543-8384 .- 1543-8392. ; 21:1, s. 143-151
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Tidskriftsartikel (refereegranskat)abstract
- Single-stranded antisense oligonucleotides (ASOs) are typically administered subcutaneously once per week or monthly. Less frequent dosing would have strong potential to improve patient convenience and increase adherence and thereby for some diseases result in more optimal therapeutic outcomes. Several technologies are available to provide sustained drug release via subcutaneous (SC) administration. ASOs have a high aqueous solubility and require relatively high doses, which limits the options available substantially. In the present work, we show that an innovative biodegradable, nonporous silica-based matrix provides zero-order release in vivo (rats) for at least 4 weeks for compositions with ASO loads of up to about 100 mg/mL (0.5 mL injection) without any sign of initial burst. This implies that administration beyond once monthly can be feasible. For higher drug loads, substantial burst release was observed during the first week. The concentrations of unconjugated ASO levels in the liver were found to be comparable to corresponding bolus doses. Additionally, infusion using a minipump shows a higher liver exposure than SC bolus administration at the same dose level and, in addition, clear mRNA knockdown and circulating protein reduction comparable to SC bolus dosing, hence suggesting productive liver uptake for a slow-release administration.
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| 3. |
- Sigfridsson, Kalle, 1964, et al.
(författare)
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A small structural change resulting in improved properties for product development
- 2015
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Ingår i: Drug Development and Industrial Pharmacy. - : Informa UK Limited. - 0363-9045 .- 1520-5762. ; 41:5, s. 866-873
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Tidskriftsartikel (refereegranskat)abstract
- AZD9343 is a water-soluble gamma amino butyric acid (GABAB) agonist intended for symptomatic relief in gastroesophageal reflux disease (GERD) patients. The compound has good chemical stability in aqueous solutions, as well as in the solid state. Only one crystal modification has been observed to date. This polymorph is slightly hygroscopic (1.5% water uptake at 80% relative humidity (RH)), which is an improvement compared to the structurally similar agonist lesogaberan (AZD3355) which liquefies at 65% RH. Since the substance is very polar and lacks a UV chromophore, conventional separation and detection techniques cannot be used to characterize the substance and its impurities. The analytical techniques are described, focusing on the capillary electrophoresis method with indirect UV detection for assay and purity, the liquid chromatographic method for enantiomeric separation with derivatization with UV chromophore and three complementary nuclear magnetic resonance (NMR) approaches (P-31-NMR, C-13-NMR and H-1-NMR) for impurities. For oral solutions, it was important to select the right concentration of phosphate buffer for the specific drug concentration and routinely use small additions of EDTA. I.V. solutions containing physiological saline as tonicity modifier could not be stored frozen at -20 degrees C. Properties of AZD9343 will be discussed in light of experiences from the structurally similar lesogaberan and (2R)-(3-amino-2-fluoropropyl) sulphinic acid (AFPSiA).
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| 4. |
- Sigfridsson, Kalle, 1964, et al.
(författare)
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Early pharmaceutical evaluation of a crystalline and hygroscopic GABA(B) receptor agonist
- 2013
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Ingår i: Drug Development and Industrial Pharmacy. - : Informa UK Limited. - 0363-9045 .- 1520-5762. ; 39:10, s. 1573-1581
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Tidskriftsartikel (refereegranskat)abstract
- Lesogaberan is a potent gamma amino butyric acid agonist and has been evaluated for its utility in treatment of gastroesophageal reflux disease. Lesogaberan is a crystalline substance that absorbs considerable amounts of water above 65% relative humidity (RH) where it also liquifies. As a result of the hygroscopicity of the zwitterionic form an investigation of different salt forms was performed. Since the test compound is polar and lacks ultraviolet (UV) chromophore, conventional separation and detection techniques could not be used to characterise the test compound and the impurities. The analytical techniques are described, focusing on the capillary electrophoresis method with indirect UV detection for purity, the liquid chromatographic method for enantiomeric separation with derivatisation with UV chromophore and two complementary nuclear magnetic resonance (NMR) approaches (F-19-NMR and H-1-NMR) for impurities. The stability study in solution showed that solutions between pH 5 and 7 were the most stable ones, but after some time degradation occurred at room temperature. When bulk lesogaberan was stored at 25 degrees C/60% RH no chemical degradation was observed after 1 year. At 40 degrees C/75% RH, where the compound liquefies, a significant degradation was observed after 1 month. However, in a closed container (= 40 degrees C) or as a napsylate salt, no degradation of lesogaberan was observed at 40 degrees C/75% RH.
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