ORCID Profile
0000-0003-0954-2976
Current Organisations
North-West University
,
Tampere University
,
ETH Zurich
,
University of Jyväskylä
,
North-West University , South Africa
,
North West University Faculty of Health Sciences
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Publisher: Elsevier BV
Date: 07-2011
DOI: 10.1016/J.IJPHARM.2011.05.003
Abstract: Artemisinins have low aqueous solubility that results in poor and erratic absorption upon oral administration. The poor solubility and erratic absorption usually translate to low bioavailability. Artemisinin-based monotherapy and combination therapies are essential for the management and treatment of uncomplicated as well as cerebral malaria. Artemisone and artemiside are novel artemisinin derivatives that have very good antimalarial activities. Pheroid™ technology is a patented drug delivery system which has the ability to entrap, transport and deliver pharmacologically active compounds. Pharmacokinetic models were constructed for artemisone and artemiside in Pheroid™ vesicle formulations. The compounds were administered at a dose of 50.0mg/kg bodyweight to C57 BL/6 mice via an oral gavage tube and blood s les were collected by means of tail-bleeding. Drug concentrations in the s les were determined using an LC/MS/MS method. There was 4.57 times more artemisone in the blood when the drug was entrapped in Pheroid™ vesicles in comparison to the drug only formulation (p < 0.0001). The absorption of artemiside was not dramatically enhanced by the Pheroid™ delivery system.
Publisher: Frontiers Media SA
Date: 29-09-2020
Publisher: American Chemical Society (ACS)
Date: 28-05-2015
Publisher: American Chemical Society (ACS)
Date: 04-02-2015
DOI: 10.1021/LA503213F
Abstract: We describe the development of a reference biosensor surface, based upon a binary mixture of oligo-ethylene glycol thiols, one of which has biotin at the terminus, adsorbed onto gold as self-assembled monolayers (SAMs). These surfaces were analyzed in detail by X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS) to establish the relationship between the thiol solution composition and the surface composition and structure. We report the use of argon cluster primary ions for the analysis of PEG-thiols, establishing that the different thiols are intimately mixed and that SIMS may be used to measure surface composition of thiol SAMs on gold with a detection limit better than 1% fractional coverage. The adsorption of neutralized chimeric avidin to these surfaces was measured simultaneously using ellipsometry and QCM-D. Comparison of the two measurements demonstrates the expected nonlinearity of the frequency response of the QCM but also reveals a strong variation in the dissipation signal that correlates with the surface density of biotin. These variations are most likely due to the difference in mechanical response of neutralized chimeric avidin bound by just one biotin moiety at low biotin density and two biotin moieties at high density. The transition between the two modes of binding occurs when the average spacing of biotin ligands approaches the diameter of the avidin molecule.
Publisher: Elsevier BV
Date: 11-2015
DOI: 10.1016/J.NANO.2015.07.010
Abstract: Artemisone is a 10-amino-artemisinin derivative that is markedly superior in vitro and in vivo to current artemisinins against malaria and also possesses antitumor activity. In seeking to capitalise on the last property, we have examined the encapsulation of artemisone in nano-vesicular niosomes and solid lipid nanoparticles, and have evaluated efficacies of the free and encapsulated artemisone against human melanoma A-375 cells and effects on human keratinocytes (HaCaT). Artemisone is successfully encapsulated into the nano-vesicles with encapsulation efficiencies of 67±6% and 79±5%, and with average particle sizes being 211±10nm and 295±18nm respectively. The formulations displayed highly selective cytotoxicity towards the melanoma cells with negligible toxicity towards the normal skin cells. The artemisone-loaded nano-vesicles almost completely inhibited the melanoma cells compared to the free drug. The results overall suggest a potentially more useful therapeutic strategy that needs to be evaluated for the treatment of melanoma and other cancers. Apart from being an effective anti-malarial drug, a surprising action of artemisone also has antitumor activity. Nonetheless, its low water solubility and bioavailability has limited its clinical use. In this article, the authors enacapsulated artemisone in nano- vesicles and solid lipid nano-particles (SLNs). In-vitro studies confirmed the selective cytotoxicity towards melanoma cells. Further in-vivo and pre-clinical studies are awaited.
Location: South Africa
No related grants have been discovered for Lissinda du Plessis.