Browsing by Author "Oosthuizen, Gert A."
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- ItemDelivery of antibiotics from cementless titanium-alloy cubes may be a novel way to control postoperative infections(Hindawi Publishing Corporation, 2015-02) Oosthuizen, Gert A.; Bezuidenhout, Martin B.; Van Staden, Anton D.; Dimitrov, Dimitar M.; Dicks, Leon Milner Theodore, 1961-; Industrial Engineering; MicrobiologyBacterial colonisation and biofilm formation onto orthopaedic devices are difficult to eradicate. In most cases infection is treated by surgical removal of the implant and cleaning of the infected area, followed by extensive treatment with broad-spectrum antibiotics. Such treatment causes great discomfort, is expensive, and is not always successful. In this study we report on the release of vancomycin through polyethersulfone membranes from channels in cementless titanium-alloy cubes. The cubes were constructed with LaserCUSING from Ti6Al4V ELI powder. Vancomycin was released by non-Fickian anomalous (constraint) diffusion. Approximately 50% of the vancomycin was released within the first 17 h. However, sustained delivery of vancomycin for 100 h was possible by reinjecting the channels. Refillable implants may be a novel way to control postoperative infections.
- ItemEmissions testing of loose biomass in Limpopo Province of South Africa(Elsevier, 2017) Shuma, Mikateko R.; Madyira, Daniel M.; Oosthuizen, Gert A.ENGLISH ABSTRACT: Southern Africa depends on wood for energy. This affects deforestation and global warming. Loose biomass briquettes can replace round wood and mitigate such problems. Loose biomass derived from agricultural and forestry waste has chemicals like pesticides which can cause unsafe emissions. This paper studies emissions resulting from combustion of such loose biomass collected from Limpopo, a province of South Africa. Twelve loose biomass samples were tested for gases emitted from domestic stove combustion. Exhaust gases were sampled and tested to determine composition and quantities of emitted elements. Both element identification and particulate analysis are reported.
- ItemTitanium-based hip stems with drug delivery functionality through additive manufacturing(Hindawi, 2015) Bezuidenhout, Martin B.; Dimitrov, Dimitar M.; Van Staden, Anton D.; Oosthuizen, Gert A.; Dicks, Leon Milner Theodore, 1961-ENGLISH ABSTRACT: Postoperative infections are a major concern in patients that receive implants.These infections generally occur in areas with poor blood flow and pathogens do not always respond to antibiotic treatment. With the latest developments in nanotechnology, the incorporation of antibiotics into prosthetic implants may soon become a standard procedure. The success will, however, depend on the ability to control the release of antibiotics at concentrations high enough to prevent the development of antibiotic-resistant strains. Through additive manufacturing, antibiotics can be incorporated into cementless femoral stems to produce prosthetic devices with antimicrobial properties. With the emerging increase in resistance to antibiotics, the incorporation of antimicrobial compounds other than antibiotics, preferably drugs with a broader spectrumof antimicrobial activity, will have to be explored.This review highlights the microorganisms associated with total hip arthroplasty (THA), discusses the advantages and disadvantages of the latest materials used in hip implants, compares different antimicrobial agents that could be incorporated, and addresses novel ideas for future research.