Browsing by Author "Maphasa, Retsepile Ephraim"

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    Immunomodulatory nanoparticles induce autophagy in macrophages and reduce mycobacterium tuberculosis burden in the lungs of mice
    (American Chemical Society, 2025) Bekale, Raymonde Bamboukou; Maphasa, Retsepile Ephraim; D’Souza, Sarah
    Tuberculosis (TB) is the leading cause of death frominfectious disease. Macrophages are the primary immune respondersand become the primary host cells for the causative agentMycobacterium tuberculosis. Following the uptake of M. tuberculosis,the inherent antimicrobial action of macrophages is dampened,enabling the bacterium to reside within these cells and multiply.Rising resistance of M. tuberculosis to antibiotics has led to theinvestigation of novel approaches for the treatment of TB. Here, wereport a host-directed approach, employing biomimetic Curdlanpoly(lactic-co-glycolic acid) (C-PLGA) nanoparticles (NPs), andexamine autophagy induction in infected macrophages, eradication ofM. tuberculosis and immune modulation in a mouse model. Wedemonstrate that the NPs induce autophagy in M. tuberculosis-infectedmacrophages. Treatment of H37Rv infected C57BL/6 mice with these NPs reduced M. tuberculosis burden in the lungs of mice andmodulated cytokines and chemokines and this work demonstrates that these immunomodulatory NPs are a potential treatmentapproach for TB
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    Investigating the effect of particle size on the antibacterial activity of gold nanoparticles
    (University of the Western Cape, 2017) Maphasa, Retsepile Ephraim; Dube, A.; Meyer, M.
    The increase of antibiotic- and/or multidrug-resistant bacteria has become a major global challenge. Killing of antibiotic-resistant bacteria requires a high dose of multiple, expensive drugs, which possess unfavourable side effects to the infected individuals. As a result, treatment of antibiotic resistant-bacteria is costly and more time is required to complete treatment. Therefore, novel substitutes are required to combat drug resistant infections while preventing further microbial resistance. Spherical gold Nanoparticles (sAuNPs) prepared using the citrate reduction method have been found to exert antibacterial activity against a number of gram positive and gram negative bacteria. However, there is still uncertainty regarding the role of size on the antibacterial activity of sAuNPs. The effect of exposure time on the antibacterial activity of sAuNPs is also still not well understood. In this study, it was hypothesized that AuNPs will show a size- and concentration-dependentantibacterial activity against selected gram positive (+) and gram negative (-) bacteria.
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    Investigating the effect of particle size on the antibacterial activity of gold nanoparticles
    (University of the Western Cape, 2017) Maphasa, Retsepile Ephraim; Dube, A.; Meyer, M.
    The increase of antibiotic- and/or multidrug-resistant bacteria has become a major global challenge. Killing of antibiotic-resistant bacteria requires a high dose of multiple, expensive drugs, which possess unfavourable side effects to the infected individuals. As a result, treatment of antibiotic resistant-bacteria is costly and more time is required to complete treatment. Therefore, novel substitutes are required to combat drug resistant infections while preventing further microbial resistance. Spherical gold Nanoparticles (sAuNPs) prepared using the citrate reduction method have been found to exert antibacterial activity against a number of gram positive and gram negative bacteria. However, there is still uncertainty regarding the role of size on the antibacterial activity of sAuNPs. The effect of exposure time on the antibacterial activity of sAuNPs is also still not well understood. In this study, it was hypothesized that AuNPs will show a size- and concentration-dependentantibacterial activity against selected gram positive (+) and gram negative (-) bacteria.