Browsing by Author "Naidoo, Kersch"

Now showing 1 - 6 of 6
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    Determination of the optical properties of PNIPAAm gels used in biological applications
    (2009-07) Singh, A; Karsten, AE; Mputle, I; Chetty, A; Naidoo, Kersch
    Poly(N-isopropylacrylamide) that is PNIPAAm is a temperature sensitive smart material which displays a lower critical solution temperature (LCST) at 33-35oC. At the lower critical solution temperature, the gel changes from hydrophilic to hydrophobic which has significant consequences in cell culturing. The first known measurements of the optical properties that is absorption (µa) and reduced scattering (µ's) coefficients, as a function of temperature, of a series of crosslinked PNIPAAm gels, using an integrating sphere setup, is presented at a wavelength of 632.8 nm. These properties showed a direct correlation between the scattering coefficient and the crosslinker density for the gels. The absorption properties correlated well with the known absorption characteristics of these gels.
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    Development of an oxygen carrier nanoemulsion for organ preservation
    (CSIR, 2010-08-31) Barnard, A; Msomi, S; Moolman, S; Naidoo, Kersch
    The current key development focus in organ preservation for transplant purposes is preservation of organs at normothermic or subnormothermic temperatures (i.e at or slightly below physiological temperature) as opposed to cold storage. The current gold standard in organ preservation for transplant is to preserve harvested organs at low temperatures while circulating an organ preservation solution through the organ. The organs however, sustain some damage when exposed to such low temperatures, a phenomenon known as ‘cold perfusion damage’. It is therefore desirable to transport the organ at temperatures closer to normal physiological conditions (i.e 25 to 37 °C). This however, substantially increases the organ’s oxygen requirement levels. A critical aspect of organ preservation at higher temperatures is thus the provision of a sufficient oxygen supply to the harvested organ so that the organ can maintain its metabolic rate and remain a viable candidate for transplant. The CSIR has developed a synthetic perfluorocarbon (PFC) based nanoemulsion that serves as an oxygen carrier for the preservation of organs. Perfluorochemicals can be used as oxygen carriers due to their exceptionally high capacity to dissolve gasses1,2. Additionally, PFC’s display high levels of chemical stability and biological inertness which makes them suitable for biological use1,2. Perfluorooctyl bromide (PFOB) is the particular PFC used in the CSIR oxygen carrier emulsion1,2.
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    Emulsion preparation for novel micro-porous polymeric hemi-shells
    (Elsevier, 2008) Naidoo, Kersch; Rolfes, H; Easton, K; Moolman, S; Chetty, A; Richter, W; Nilen, R
    A modified oil-in-water (O/W) emulsion process was developed to produce novel micro-porous hemi-spherical polycaprolactone (PCL) micro-particles called "hemi-shells". By addition of a porogen such as sodium bicarbonate (NaHCO3) into the PCL-dichloromethane (DCM) oil phase and emulsification in an acidic polyvinyl alcohol (PVA) aqueous phase, micro-porous hemi-shells formed as solvent evaporated. CO2 gas evolution from the porogen created particles with an externally micro-porous shell and a large internal cavity. The hemi-shells were characterized by SEM and optical microscopy. The number-average particle yield in the 50-200 µm range was 84%. The number-average hemi-shell yield in the same size range was 41%. These novel micro-particles have potential applications in tissue engineering and drug delivery
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    Extraction of siphonochilus aethiopicus essential oil by steam distillation
    (Taylor & Francis, 2017-04) Malaka, MS; Naidoo, Kersch; Kabuba, J
    Siphonochilus aethiopicus is an indigenous South African plant also known as African ginger. It has often been used for its medicinal properties to treat various ailments such as flu, colds, and so forth. The research aim of this study was to optimize the process parameters of steam distillation for the extraction of oil from African ginger rhizomes. This technology is the oldest and well known for extracting essential oils due to its economic viability and the higher final oil purity. The effects of operating parameters such as extraction duration, moisture content, particle size, and temperatures between 80°C and 100°C were studied for maximum oil recovery. The oil recovery of 0.61% (w/w) was achieved after 270 min of extraction time, using 6.37% (dry) moisture content of particle size 2.4 mm–4 mm at a maximum temperature of 100°C. Fick’s first law was used to mathematically model the experimental data of this study.
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    Improving lives through a bioartificial liver support system
    (CSIR, 2008-11) Naidoo, Kersch; Moolman, FS
    This poster covers the development of a technology towards a novel bioartificial liver support system (BALSS) that is capable of providing liver functions, in patients with acute liver failure, while housed outside the body (extra corporeal). This novel system was co-developed by the University of Pretoria and the CSIR and is now proprietary.
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    Injection resorbable polymer shells for soft tissue augmentation
    (CSIR, 2008-11) Naidoo, Kersch; Rolfes, H; Easton, K; Moolman, FS; Chetty, A; Richter, PW; Nilen, R; Kotze, L
    CSIR researchers have developed an injectable, resorbable soft tissue bulking product that has potential applications in fields ranging from heart and recontructive surgery, to minimally invasive cosmetic surgery. Biomaterials research is very relevant to developing nations, especially due to the high injury-related burden of disease and defects due to insufficient pre-natal care amongst the poor and disadvantaged. This research focuses on producing a locally-manufactured resorbable biopolymeric particle system for use in soft tissue augmentation. This research has resulted in a patent application that has received a positive international preliminary report on patentability that will facilitate the eventual commercialisation of this unique product.