| 1. |
- Ezzat, Kariem, et al.
(författare)
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PepFect 14, a novel cell-penetrating peptide for oligonucleotide delivery in solution and as solid formulation
- 2011
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Ingår i: Nucleic Acids Research. - : Oxford University Press (OUP). - 0305-1048 .- 1362-4962. ; 39:12, s. 5284-5298
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Tidskriftsartikel (refereegranskat)abstract
- Numerous human genetic diseases are caused by mutations that give rise to aberrant alternative splicing. Recently, several of these debilitating disorders have been shown to be amenable for splice-correcting oligonucleotides (SCOs) that modify splicing patterns and restore the phenotype in experimental models. However, translational approaches are required to transform SCOs into usable drug products. In this study, we present a new cell-penetrating peptide, PepFect14 (PF14), which efficiently delivers SCOs to different cell models including HeLa pLuc705 and mdx mouse myotubes; a cell culture model of Duchenne's muscular dystrophy (DMD). Non-covalent PF14-SCO nanocomplexes induce splice-correction at rates higher than the commercially available lipid-based vector Lipofectamine™ 2000 (LF2000) and remain active in the presence of serum. Furthermore, we demonstrate the feasibility of incorporating this delivery system into solid formulations that could be suitable for several therapeutic applications. Solid dispersion technique is utilized and the formed solid formulations are as active as the freshly prepared nanocomplexes in solution even when stored at an elevated temperatures for several weeks. In contrast, LF2000 drastically loses activity after being subjected to same procedure. This shows that using PF14 is a very promising translational approach for the delivery of SCOs in different pharmaceutical forms.
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| 2. |
- Ezzat, Kariem, et al.
(författare)
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Scavenger receptor-mediated uptake of cell-penetrating peptide nanoparticles with oligonucleotides
- 2012
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Ingår i: The FASEB Journal. - : Wiley. - 0892-6638 .- 1530-6860. ; 26:3, s. 1172-1180
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Tidskriftsartikel (refereegranskat)abstract
- Cell-penetrating peptides (CPPs) are shortcationic peptides that penetrate cells by interacting withthe negatively charged plasma membrane; however, thedetailed uptake mechanism is not clear. In contrary to theconventional mode of action of CPPs, we show here thata CPP, PepFect14 (PF14), forms negatively charged nanocomplexeswith oligonucleotides and their uptake is mediatedby class-A scavenger receptors (SCARAs). Specificinhibitory ligands of SCARAs, such as fucoidin, polyinosinicacid, and dextran sulfate, totally inhibit the activityof PF14-oligonucleotide nanocomplexes in the HeLapLuc705 splice-correction cell model, while nonspecific,chemically related molecules do not. Furthermore, RNAinterference (RNAi) knockdown of SCARA subtypes(SCARA3 and SCARA5) that are expressed in this cell lineled to a significant reduction of the activity to <50%. Inline with this, immunostaining shows prevalent colocalizationof the nanocomplexes with the receptors, and electronmicroscopy images show no binding or internalizationof the nanocomplexes in the presence of theinhibitory ligands. Interestingly, naked oligonucleotidesalso colocalize with SCARAs when used at high concentrations.These results demonstrate the involvement ofSCARA3 and SCARA5 in the uptake of PF14-oligonucleotidenanocomplexes and suggest for the first time thatsome CPP-based systems function through scavenger receptors,which could yield novel possibilities to understandand improve the transfection by CPPs.
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| 3. |
- Fadel, Hani T, 1979, et al.
(författare)
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Clinical and biological indicators of dental caries and periodontal disease in adolescents with or without obesity.
- 2014
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Ingår i: Clinical oral investigations. - : Springer Science and Business Media LLC. - 1436-3771 .- 1432-6981. ; 18:2, s. 359-368
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: This study aims to assess clinical, microbiological and inflammatory parameters as indicators for caries and periodontal disease in adolescents with obesity. MATERIAL AND METHODS: Twenty-seven adolescents with obesity [body mass index (BMI) 37±4kg/m(2)] and 28 controls (BMI 20±2kg/m(2)) answered questionnaires and were investigated regarding salivary parameters, plaque pH drop after a 1-min glucose rinse, oral clinical parameters, inflammatory markers in gingival crevicular fluid (GCF) and sub-gingival mirobiota. RESULTS: Compared with controls, adolescents with obesity had a lower stimulated salivary secretion rate (1.55±0.63 vs. 2.05±1.05mL/min, p<0.05), higher concentrations of secretory immunoglobulin A (sIgA) (p<0.001), more decayed tooth surfaces (3.4±6.6 vs. 0.8±1.1, p<0.05) and more gingivitis (p<0.01) after controlling for possible confounders. Overall, similar snacking habits, plaque amounts and numbers of deep periodontal pockets were observed. Following the glucose rinse, a slightly more pronounced drop in plaque pH was observed in the obesity group (p>0.05). No differences in sub-gingival inflammatory or microbial indicators were detected (p>0.01). CONCLUSIONS: More caries and gingival inflammation were observed in adolescents with obesity. Of the indicators tested, salivary secretion rate was lower and sIgA levels were higher in the obesity group. We are unable to confirm whether differences in caries and gingival inflammation are due to systemic changes that are associated with obesity or due to possible irregular dietary/oral hygiene habits. CLINICAL RELEVANCE: Customised oral health preventive programmes and appropriate collaboration with medical personnel in selecting the best diet, medication and psychological support can help improve the general well-being, including oral health, of children with obesity. This may even reduce the risk of oral diseases.
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| 4. |
- Lindberg, Staffan, 1979-, et al.
(författare)
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A convergent uptake route for peptide- and polymer-based nucleotide delivery systems
- 2015
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Ingår i: Journal of Controlled Release. - : Elsevier BV. - 0168-3659 .- 1873-4995. ; 206, s. 58-66
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Tidskriftsartikel (refereegranskat)abstract
- Cell-penetrating peptides (CPPs) have been used as vehicles to deliver various cargos into cells and are promising as tools to deliver therapeutic biomolecules such as oligonucleotides both in vitro and in vivo. CPPs are positively charged and it is believed that CPPs deliver their cargo in a receptor-independent manner by interactingwith the negatively charged plasmamembrane and thereby inducing endocytosis. In this study we examine the mechanism of uptake of several different, well known, CPPs that form complexes with oligonucleotides.We show that these CPP:oligonucleotide complexes are negatively charged in transfection-media and their uptake is mediated by class A scavenger receptors (SCARA). These receptors are known to promiscuously bind to, and mediate uptake of poly-anionic macromolecules. Uptake of CPP:oligonucleotide complexes was abolished using pharmacological SCARA inhibitors as well as siRNA-mediated knockdown of SCARA. Additionally, uptake of CPP:oligonucleotide was significantly increased by transiently overexpressing SCARA. Furthermore, SCARA inhibitors also blocked internalization of cationic polymer:oligonucleotide complexes.Our results demonstrate that the previous held belief that CPPs act receptor independently does not hold true for CPP:oligonucleotide complexes, as scavenger receptor class A (SCARA) mediates the uptake of all the examined CPP:oligonucleotide complexes in this study.
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| 5. |
- Lindberg, Staffan, 1979-
(författare)
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Cell-penetrating peptides for oligonucleotide delivery : Design and uptake mechanisms
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The use of oligonucleotides for gene therapy has the potential to efficiently treat a plethora of diseases with minimal side effects. However, the use of oligonucleotides is hampered by the properties of these molecules, which make it essentially impossible for them to permeate the cellular membrane. Therefore, a great deal of research has been focused on developing delivery vectors, which can efficiently and safely deliver oligonucleotides into cells. Cell-penetrating peptides (CPPs) constitute a class of delivery vectors that have received much attention since they were discovered over 20 years ago. CPPs can deliver a wide variety of cargos into cells, such as small molecules, proteins, oligonucleotides and particles, in an efficacious and non-toxic manner.In this thesis two new CPPs for oligonucleotide delivery were designed. The purpose of the design was to create CPPs, which form stable complexes with oligonucleotides and have endosomolytic properties. The new peptides showed superior potency in intracellular oligonucleotide delivery compared to previously reported CPPs. These results demonstrate that it is possible to drastically improve the efficiency of existing CPPs with relatively simple modifications.It is well known that CPPs use endocytosis to gain entry into cells, however, why cells endocytose CPPs has never been clearly established. In this thesis we determine that several CPP:oligonucleotide complexes interact with scavenger receptors, and that this interaction leads to endocytosis. The results presented in this thesis provides a deeper understanding of how CPPs function and thereby insights how to improve CPP design.
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| 6. |
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| 7. |
- Lindberg, Staffan, 1979-, et al.
(författare)
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PepFect15, a novel endosomolytic cell-penetrating peptide for oligonucleotide delivery via scavenger receptors
- 2012
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Ingår i: International Journal of Pharmaceutics. - : Elsevier BV. - 0378-5173 .- 1873-3476. ; 441:1-2, s. 242-247
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Tidskriftsartikel (refereegranskat)abstract
- Gene-regulatory biomolecules such as splice-correcting oligonucleotides and anti-microRNA oligonucleotides are important tools in the struggle to understand and treat genetic disorders caused by defective gene expression or aberrant splicing. However, oligonucleotides generally suffer from low bioavailability, hence requiring efficient and non-toxic delivery vectors to reach their targets. Cell-penetrating peptides constitute a promising category of carrier molecules for intracellular delivery of bioactive cargo. In this study we present a novel cell-penetrating peptide, PepFect15, comprising the previously reported PepFect14 peptide modified with endosomolytic trifluoromethylquinoline moieties to facilitate endosomal escape. Pepfect15 efficiently delivers both splice-correcting oligonucleotides and anti-microRNA oligonucleotides into cells through a non-covalent complexation strategy. To our knowledge this is the first work that describes peptide-mediated anti-microRNA delivery. The peptide and its cargo form stable, negatively charged nanoparticles that are taken up by cells largely through scavenger receptor type A mediated endocytosis.
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| 8. |
- Lindberg, Staffan, 1979-
(författare)
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Rational design of novel cell-penetrating peptides
- 2012
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Although cell-penetrating peptides (CPPs) have been an active field of research for over 20 years there are still properties such as efficiency and stability that must be improved for CPPs to reach their full potential as delivery vectors.In this thesis two peptides were designed for non-covalent oligonucleotide delivery, in an attempt to overcome two major issues hampering wider use of CPPs, namely low stability and endosomal entrapment.In Paper I we designed a new peptide named PepFect14, which has unnatural amino-acid ornithine as the source of positive charge, to address the stability issue. PepFect14 was shown to deliver SCOs in a highly efficient manner into different cell-lines. Furthermore, formulation of non-covalent PepFect14:SCO complexes into solid form, suitable for storage and transportation, was developed. The formulated complexes were stable for weeks and retained high activity.In Paper II we modified PepFect14 with endosomolytic groups to facilitate endosomal escape, the resulting peptide was named PepFect15. Delivery of SCO and miRNA was efficiently mediated by PepFect15 into HeLa cells and endosomolytic property was validated. Additionally, uptake of Pepfect15:SCO complexes was shown to be mediated by scavenger receptor class A.
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| 9. |
- Lührmann, Anna, et al.
(författare)
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Democracy for All?
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- V-Dem Annual Democracy Report 2018
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| 10. |
- Lührmann, Anna, 1983, et al.
(författare)
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State of the world 2017: autocratization and exclusion?
- 2018
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Ingår i: Democratization. - : Informa UK Limited. - 1351-0347 .- 1743-890X. ; 25:8, s. 1321-1340
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Tidskriftsartikel (refereegranskat)abstract
- This article presents evidence of a global trend of autocratization. The most visible feature of democracy – elections – remains strong and is even improving in some places. Autocratization mainly affects non-electoral aspects of democracy such as media freedom, freedom of expression, and the rule of law, yet these in turn threaten to undermine the meaningfulness of elections. While the majority of the world’s population lives under democratic rule, 2.5 billion people were subjected to autocratization in 2017. Last year, democratic qualities were in decline in 24 countries across the world, many of which are populous such as India and the United States. This article also presents evidence testifying that men and wealthy groups tend to have a strong hold on political power in countries where 86% of the world population reside. Further, we show that political exclusion based on socio-economic status in particular is becoming increasingly severe. For instance, the wealthy have gained significantly more power in countries home to 1.9 billion of the world’s population over the past decade.
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