| 1. |
- Björn, Camilla, et al.
(författare)
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Anti-infective efficacy of the lactoferrin-derived antimicrobial peptide HLR1r
- 2016
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Ingår i: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 81, s. 21-28
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Tidskriftsartikel (refereegranskat)abstract
- Antimicrobial peptides (AMPs) have emerged as a new class of drug candidates for the treatment of infectious diseases. Here we describe a novel AMP, HLR1r, which is structurally derived from the human milk protein lactoferrin and demonstrates a broad spectrum microbicidal action in vitro. The minimum concentration of HLR1r needed for killing >= 99% of microorganisms in vitro, was in the range of 3-50 mu g/ml for common Gram-negative and Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), and for the yeast Candida albicans, when assessed in diluted brain-heart infusion medium. We found that HLR1r also possesses anti-inflammatory properties as evidenced by inhibition of tumor necrosis factor alpha (TNF-alpha) secretion from human monocyte-derived macrophages and by repression of interleukin-6 (IL-6) and plasminogen activator inhibitor-1 (PAI-1) secretion from human mesothelial cells, without any cytotoxic effect observed at the concentration range tested (up to 400 mu g/ml). HLR1r demonstrated pronounced anti-infectious effect in in vivo experimental models of cutaneous candidiasis in mice and of excision wounds infected with MRSA in rats as well as in an ex vivo model of pig skin infected with S. aureus. In conclusion, HLR1r may constitute a new therapeutic alternative for local treatment of skin infections. (C) 2016 Elsevier Inc. All rights reserved.
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| 2. |
- Borde, Annika, 1979, et al.
(författare)
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Preparation and evaluation of a freeze-dried oral killed cholera vaccine formulation
- 2011
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Ingår i: European journal of pharmaceutics and biopharmaceutics. - : Elsevier BV. - 0939-6411 .- 1873-3441. ; 79:3, s. 508-518
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Tidskriftsartikel (refereegranskat)abstract
- Different oral liquid cholera vaccines have proved to be safe and effective, but their formulations present problems for use in low-income countries, since large package volumes have to be transported and cold chain maintenance is required. A solid state formulation would here be more advantageous, and consequently, the possibility to develop a dry cholera vaccine formulation by freeze-drying was investigated. The ability of sucrose, trehalose and mannitol to provide process stabilization during freeze-drying was tested on a formalin-killed whole-cell Vibrio cholerae model vaccine. A matrix of sucrose or trehalose prevented bacterial aggregation, preserved cell morphology and maintained practically completely the protective lipopolysaccharide (LPS) antigen on the cell surface and its reactivity with specific antibody in vitro. After reconstitution, this formulation also retained the capacity to elicit a strong serum and gut mucosal anti-LPS antibody response in orally immunized mice, as compared to the corresponding liquid vaccine formulation. The full preservation of the in vivo immunogenicity was also maintained when the internationally widely licensed oral cholera vaccine Dukoral (TM), which comprises a cocktail of inactivated V. cholerae together with cholera toxin B-subunit (CTB), was freeze-dried using sucrose for stabilization. Thus, we present a process generating a dry oral inactivated whole-cell cholera vaccine formulation with attractive features for public health use in cholera-afflicted settings.
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| 3. |
- Boge, Lukas, et al.
(författare)
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Peptide-Loaded Cubosomes Functioning as an Antimicrobial Unit against Escherichia coli
- 2019
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society. - 1944-8244 .- 1944-8252. ; 11:24, s. 21314-21322
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Tidskriftsartikel (refereegranskat)abstract
- Dispersions of cubic liquid crystalline phases, also known as cubosomes, have shown great promise as delivery vehicles for a wide range of medicines. Due to their ordered structure, comprising alternating hydrophilic and hydrophobic domains, cubosomes possess unique delivery properties and compatibility with both water-soluble and -insoluble drugs. However, the drug delivery mechanism and cubosome interaction with human cells and bacteria are still poorly understood. Herein, we reveal how cubosomes loaded with the human cathelicidin antimicrobial peptide LL-37, a system with high bacteria-killing effect, interact with the bacterial membrane and provide new insights into the eradication mechanism. Combining the advanced experimental techniques neutron reflectivity and quartz crystal microbalance with dissipation monitoring, a mechanistic drug delivery model for LL-37-loaded cubosomes on bacterial mimicking bilayers was constructed. Moreover, the cubosome interaction with Escherichia coli was directly visualized using super-resolution laser scanning microscopy and cryogenic electron tomography. We could conclude that cubosomes loaded with LL-37 adsorbed and distorted bacterial membranes, providing evidence that the peptide-loaded cubosomes function as an antimicrobial unit.
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| 4. |
- Cappelletto, Elia, et al.
(författare)
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Impact of Post Manufacturing Handling of Protein-Based Biologic Drugs on Product Quality and User Centricity
- 2024
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Ingår i: Journal of Pharmaceutical Sciences. - : Elsevier. - 0022-3549 .- 1520-6017.
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Tidskriftsartikel (refereegranskat)abstract
- This article evaluates the current gaps around the impact of post-manufacturing processes on the product qualities of protein-based biologics, with a focus on user centricity. It includes the evaluation of the regulatory guidance available, describes a collection of scientific literature and case studies to showcase the impact of post-manufacturing stresses on product and dosing solution quality. It also outlines the complexity of clinical handling and the need for communication, and alignment between drug providers, healthcare professionals, users, and patients. Regulatory agencies provide clear expectations for drug manufacturing processes, however, guidance supporting post-product manufacturing handling is less defined and often misaligned. This is problematic as the pharmaceutical products experience numerous stresses and processes which can potentially impact drug quality, safety and efficacy. This article aims to stimulate discussion amongst pharmaceutical developers, health care providers, device manufacturers, and public researchers to improve these processes. Patients and caregivers' awareness can be achieved by providing relevant educational material on pharmaceutical product handling.
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| 5. |
- Andersson, Helene, 1983, et al.
(författare)
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Effects of molecular weight on permeability and microstructure of mixed ethyl-hydroxypropyl-cellulose films
- 2013
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Ingår i: European Journal of Pharmaceutical Sciences. - : Elsevier BV. - 0928-0987 .- 1879-0720. ; 48:1-2, s. 240-248
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Tidskriftsartikel (refereegranskat)abstract
- Films of ethyl cellulose (EC) and water-soluble hydroxypropyl cellulose (HPC) can be used for extended release coatings in oral formulations. The permeability and microstructure of free EC/HPC films with 30% w/w HPC were studied to investigate effects of EC molecular weight. Phase separation during film spraying and subsequent HPC leaching after immersion in aqueous media cause pore formation in such films. It was found that sprayed films were porous throughout the bulk of the films after water immersion. The molecular weight affected HPC leaching, pore morphology and film permeability; increasing the molecular weight resulted in decreasing permeability. A model to distinguish the major factors contributing to diffusion retardation in porous films showed that the trend in permeability was determined predominantly by factors associated with the geometry and arrangement of pores, independent of the diffusing species. The film with the highest molecular weight did, however, show an additional contribution from pore wall/permeant interactions. In addition, rapid drying and increasing molecular weight resulted in smaller pores, which suggest that phase separation kinetics affects the final microstructure of EC/HPC films. Thus, the molecular weight influences the microstructural features of pores, which are crucial for mass transport in EC/HPC films.
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| 6. |
- Rao, Komal Umashankar, et al.
(författare)
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A broad spectrum anti-bacterial peptide with an adjunct potential for tuberculosis chemotherapy
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Alternative ways to prevent and treat infectious diseases are needed. Previously, we identified a fungal peptide, NZX, that was comparable to rifampicin in lowering M. tuberculosis load in a murine tuberculosis (TB) infection model. Here we assessed the potential synergy between this cationic host defence peptide (CHDP) and the current TB drugs and analysed its pharmacokinetics. We found additive effect of this peptide with isoniazid and ethambutol and confirmed these results with ethambutol in a murine TB-model. In vivo, the peptide remained stable in circulation and preserved lung structure better than ethambutol alone. Antibiotic resistance studies did not induce mutants with reduced susceptibility to the peptide. We further observed that this peptide was effective against nontuberculous mycobacteria (NTM), such as M. avium and M. abscessus, and several Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus. In conclusion, the presented data supports a role for this CHDP in the treatment of drug resistant organisms.
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| 7. |
- Barreto Henriksson, Helena, et al.
(författare)
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Determination of mechanical and rheological properties of a cell-loaded peptide gel during ECM production
- 2019
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Ingår i: International Journal of Pharmaceutics. - : Elsevier BV. - 0378-5173 .- 1873-3476. ; 563, s. 437-444
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Tidskriftsartikel (refereegranskat)abstract
- The development of an injectable biomaterial that supports cell survival and maintains or promotes nucleus pulposus (NP) phenotype could aid delivery of cells to degenerated NPs causing low back pain. Mesenchymal cells were loaded and grown in a synthetic peptide gel, PuraMatrix (R). Cells were observed within the gels over 0-28 days, and accumulation of glycosaminoglycans were detected by histological staining. The mechanical properties of the cell-loaded constructs, and the change of the mechanical properties were studied using stress relaxation of the gels under compression and confinement. The PuraMatrix (R) gel was shown to relax fast on compression indicating that the fluid could easily flow out of the gel, and thus indicating the presence of large pores/voids. The presence of these pores/voids was further supported by high mobility of dextran molecules, determined using fluorescence recovery after photo bleaching. The stress required to deform the cell-loaded constructs to a specific strain increases at day 21, at which point the presence of glycosaminoglycans within the cell-loaded constructs was also observed. The results provide evidence of changes in mechanical properties of the PuraMatrix (R) matrix upon excretion of the extracellular matrix by the cells.
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| 8. |
- Larsson, Mikael, 1982, et al.
(författare)
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The influence of HPMC substitution pattern on solid state properties
- 2010
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 82:4, s. 1074-1081
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Tidskriftsartikel (refereegranskat)abstract
- The solid-state properties were studied for different batches of hydroxypropyl methylcellulose (HPMC). The batches had similar chemical composition, but different degree of heterogeneity with regard to the distribution of the substituents along the polymer chains. The glass transition temperature, Tg, was analysed using a new developed method where dynamic mechanic analysis, DMA, was performed in compression mode on compacts, utilizing a wedge-shaped probe. The method was verified by conventional DMA on films. Molecular interactions were studied using FT-IR. In addition, the water vapour sorption was determined by gravimetric measurements and the plasticization by water vapour was studied on film samples using DMA. The results revealed a linear relationship between increasing Tg and increasing percent glucose liberated after enzyme hydrolysis. The percent glucose liberated can in turn be considered to account for both the heterogeneity of the substituents and the total degree of substitution. The results indicated that more heterogeneously substituted cellulose derivatives and derivates with a lower degree of substitution had stronger interactions between polymer chains. As expected from these results, some small difference in the plasticization by water vapour could be detected. However, no significant differences were found in molecular interactions using FT-IR or in the sorption of water vapour. The correlation between heterogeneity in the distribution of the substituents and Tg is of much interest as heterogeneously substituted batches of HPMC have been previously shown to exhibit very different behaviour in solution and in gelling tablets.
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| 9. |
- Svagan, Anna J., et al.
(författare)
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Solid cellulose nanofiber based foams – Towards facile design of sustained drug delivery systems
- 2016
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Ingår i: Journal of Controlled Release. - : Elsevier BV. - 0168-3659 .- 1873-4995. ; 244, s. 74-82
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Tidskriftsartikel (refereegranskat)abstract
- Control of drug action through formulation is a vital and very challenging topic within pharmaceutical sciences. Cellulose nanofibers (CNF) are an excipient candidate in pharmaceutical formulations that could be used to easily optimize drug delivery rates. CNF has interesting physico-chemical properties that, when combined with surfactants, can be used to create very stable air bubbles and dry foams. Utilizing this inherent property, it is possible to modify the release kinetics of the model drug riboflavin in a facile way. Wet foams were prepared using cationic CNF and a pharmaceutically acceptable surfactant (lauric acid sodium salt). The drug was suspended in the wet-stable foams followed by a drying step to obtain dry foams. Flexible cellular solid materials of different thicknesses, shapes and drug loadings (up to 50 wt%) could successfully be prepared. The drug was released from the solid foams in a diffusion-controlled, sustained manner due to the presence of intact air bubbles which imparted a tortuous diffusion path. The diffusion coefficient was assessed using Franz cells and shown to be more than one order of magnitude smaller for the cellular solids compared to the bubble-free films in the wet state. By changing the dimensions of dry foams while keeping drug load and total weight constant, the drug release kinetics could be modified, e.g. a rectangular box-shaped foam of 8 mm thickness released only 59% of the drug after 24 h whereas a thinner foam sample (0.6 mm) released 78% of its drug content within 8 h. In comparison, the drug release from films (0.009 mm, with the same total mass and an outer surface area comparable to the thinner foam) was much faster, amounting to 72% of the drug within 1 h. The entrapped air bubbles in the foam also induced positive buoyancy, which is interesting from the perspective of gastroretentive drug-delivery.
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| 10. |
- Waqas, Muhammad, 1983, et al.
(författare)
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In vitro models for simulating swallowing
- 2017
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Ingår i: Medical radiology. - Cham : Springer International Publishing. - 9783319685717 ; , s. 549-562, s. 549-562
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter gives an overview of the in vitro models that are currently used for studying swallowing. The focus is on the construction, geometry, and performance of mechanical models. Swallowing simulations and mathematical modeling are also considered. The in vitro models that are concerned with the oral, pharyngeal, and esophageal phases of swallowing linked to bolus properties are discussed. The pharyngeal phase is given special consideration, as it is involved in both food transport to the stomach and air transport to the lungs, and therefore constitutes the most critical phase of swallowing.
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