In vitro evaluation of vernonia amygdalina gold nanoparticles to stimulate apoptosis in breast cancer lines
- Authors: Pali, Zenande
- Date: 2022-12
- Subjects: Breast--Cancer--Treatment--Technological innovations , Apoptosis -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59933 , vital:62696
- Description: Breast cancer is the most prevalent cancer in women and triple negative breast cancer (TNBC) is one of the most aggressive breast cancer subtypes. Current breast cancer therapies are associated with several side effects and less effective treatment. Therefore, the development of new approaches to improve cancer treatment are needed. The use of gold nanoparticles (AuNPs) for anti-cancer effects is one of the most promising research areas in the field of nanotechnology, because nanoparticles are readily functionalized and can passively accumulate at the tumor site without affecting healthy tissues. The green synthesis of AuNPs is an eco-friendly, costeffective, fast, and non-toxic method that is associated with fewer side effects.The aim of this study was to evaluate the cytotoxicity and apoptotic activity exhibted by Vernonia amygdalina gold nanoparticles (VA-AuNPs) in triple negative breast cancer cell lines. The aqueous extract of Vernonia amygdalina was used to reduce gold salts to form VA-AuNPs. The VA-AuNPs were synthesised at a temperature of 100 °C and pH 7. The synthesised green AuNPs were charactised using ultraviolet-visible spectroscopy, dynamic light scattering, and high resolution transmission electron microscopy. Spherical VA-AuNPs were succesfully synthesized with average size of 17.11 ± 2.82 nm and a zeta potential of -36.55 ± 1.15 mV. The MTT assay revealed that VA-AuNPs significantly reduced (p cell viability for both mouse (E0771) and human (MDA-MB231) TNBC cell lines in a dose-dependent manner. The PrestoBlue assay showed a consistent decrease in cell numbers over time, suggesting either a decrease in proliferation or increase in apoptosis. The apoptotic effects of VAAuNPs were assessed using the CaspGLOW Fluorescein active caspase-8 staining kit. It indicated that caspase 8 was activated when cells were treated with VA-AuNPs. E0771 and MDA-MB231 cells were compared when treated with VA-AuNP and a similar trend was established. The HRTEM image showed VA-AuNPs in an vesiclelike structure inside the cell. It can be concluded that the VA-AuNPs showed anticancer activities against TNBC cells. Caspase 8 is activated by VA-AuNPs, confirming the induction of apoptosis, but does not exclude the activation of the intrinsic apoptotic pathway or inhibition of proliferation activity. E0771 and MDA-MB231 cells showed similar cytotoxic activity and thus expected that the mechanism of action in these cell lines should also be similar. Future in vivo research, using the mouse model inoculated with E0771 TNBC cells, should be justified and comparable with human TNBC cells. , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-12
- Authors: Pali, Zenande
- Date: 2022-12
- Subjects: Breast--Cancer--Treatment--Technological innovations , Apoptosis -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59933 , vital:62696
- Description: Breast cancer is the most prevalent cancer in women and triple negative breast cancer (TNBC) is one of the most aggressive breast cancer subtypes. Current breast cancer therapies are associated with several side effects and less effective treatment. Therefore, the development of new approaches to improve cancer treatment are needed. The use of gold nanoparticles (AuNPs) for anti-cancer effects is one of the most promising research areas in the field of nanotechnology, because nanoparticles are readily functionalized and can passively accumulate at the tumor site without affecting healthy tissues. The green synthesis of AuNPs is an eco-friendly, costeffective, fast, and non-toxic method that is associated with fewer side effects.The aim of this study was to evaluate the cytotoxicity and apoptotic activity exhibted by Vernonia amygdalina gold nanoparticles (VA-AuNPs) in triple negative breast cancer cell lines. The aqueous extract of Vernonia amygdalina was used to reduce gold salts to form VA-AuNPs. The VA-AuNPs were synthesised at a temperature of 100 °C and pH 7. The synthesised green AuNPs were charactised using ultraviolet-visible spectroscopy, dynamic light scattering, and high resolution transmission electron microscopy. Spherical VA-AuNPs were succesfully synthesized with average size of 17.11 ± 2.82 nm and a zeta potential of -36.55 ± 1.15 mV. The MTT assay revealed that VA-AuNPs significantly reduced (p cell viability for both mouse (E0771) and human (MDA-MB231) TNBC cell lines in a dose-dependent manner. The PrestoBlue assay showed a consistent decrease in cell numbers over time, suggesting either a decrease in proliferation or increase in apoptosis. The apoptotic effects of VAAuNPs were assessed using the CaspGLOW Fluorescein active caspase-8 staining kit. It indicated that caspase 8 was activated when cells were treated with VA-AuNPs. E0771 and MDA-MB231 cells were compared when treated with VA-AuNP and a similar trend was established. The HRTEM image showed VA-AuNPs in an vesiclelike structure inside the cell. It can be concluded that the VA-AuNPs showed anticancer activities against TNBC cells. Caspase 8 is activated by VA-AuNPs, confirming the induction of apoptosis, but does not exclude the activation of the intrinsic apoptotic pathway or inhibition of proliferation activity. E0771 and MDA-MB231 cells showed similar cytotoxic activity and thus expected that the mechanism of action in these cell lines should also be similar. Future in vivo research, using the mouse model inoculated with E0771 TNBC cells, should be justified and comparable with human TNBC cells. , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-12
An evaluation of hibiscus sabdariffa gold nanoparticles for the treatment of triple negative breast cancer
- Authors: Reddy, Nireshini
- Date: 2022-12
- Subjects: Breast--Cancer--Treatment--Technological innovations , Nanomedicine – South Africa , Roselle
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59945 , vital:62697
- Description: Cancer is responsible for the millions of deaths worldwide every year, being ranked as the second leading cause of mortality in the world. Triple negative breast cancer (TNBC) is the most severe type of breast cancer, as it is the most aggressive and difficult to treat. Current treatment methods involve surgery, hormonal-, radiation- and chemotherapy. These are costly and often have severe adverse effects. There has been increasing research in the development of alternative treatment methods to reduce the side effects of cancer therapeutics, as well as the cost. The rapidly growing field of nanotechnology has allowed for the incorporation of several diagnostic, targeting, and therapeutic agents into nanomaterials for cancer treatment. The application of gold nanoparticles (AuNPs) in the diagnosis and treatment of various types of cancers has been widely investigated. AuNPs vary in size, shape, and structure, allowing for the development of diverse formulations for various treatments. The use of green materials, particularly plant material, to synthesise nanomaterials has allowed for the safe, cost-friendly and eco-friendly production of AuNPs that can be used to treat TNBC. The aim of this study was to evaluate the efficiency of green AuNPs synthesised with Hibiscus sabdariffa to treat TNBC in a pilot murine model. Spherical AuNPs were synthesised using an aqueous extract of the calyces of this plant. The AuNPs were characterised using UV-Vis spectrometry, dynamic light scattering, high resolution – transmission electron microscopy, and in vitro stability testing. A cell viability assay showed that these AuNPs exhibited cytotoxicity towards E0771 cells in a dose-dependent manner, where cells treated with the highest concentration of AuNPs (250 µg/mL) exhibited the lowest cell viability (7%). During the in vivo pilot study, C57BL/6 mice were inoculated with TNBC using the E0771 cells. It was found that TNBC had rapidly spread, resulting in metastasis in the liver, as well as omentum and mesentery. This resulted in a number of mice dying; therefore, shortening treatment time of the AuNPs. It is suggested that AuNP treatment may have exacerbated mouse death by promoting ROS production in metastasised tissue, suggesting that AuNP treatment may not be suitable for stage 4 TNBC. Tumor analysis of caspase-3 content showed that the AuNPs exhibited potential pro-apoptotic activity in the tumours, prompting further research into the tumour uptake and apoptotic mechanism of these AuNPs. , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-12
- Authors: Reddy, Nireshini
- Date: 2022-12
- Subjects: Breast--Cancer--Treatment--Technological innovations , Nanomedicine – South Africa , Roselle
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59945 , vital:62697
- Description: Cancer is responsible for the millions of deaths worldwide every year, being ranked as the second leading cause of mortality in the world. Triple negative breast cancer (TNBC) is the most severe type of breast cancer, as it is the most aggressive and difficult to treat. Current treatment methods involve surgery, hormonal-, radiation- and chemotherapy. These are costly and often have severe adverse effects. There has been increasing research in the development of alternative treatment methods to reduce the side effects of cancer therapeutics, as well as the cost. The rapidly growing field of nanotechnology has allowed for the incorporation of several diagnostic, targeting, and therapeutic agents into nanomaterials for cancer treatment. The application of gold nanoparticles (AuNPs) in the diagnosis and treatment of various types of cancers has been widely investigated. AuNPs vary in size, shape, and structure, allowing for the development of diverse formulations for various treatments. The use of green materials, particularly plant material, to synthesise nanomaterials has allowed for the safe, cost-friendly and eco-friendly production of AuNPs that can be used to treat TNBC. The aim of this study was to evaluate the efficiency of green AuNPs synthesised with Hibiscus sabdariffa to treat TNBC in a pilot murine model. Spherical AuNPs were synthesised using an aqueous extract of the calyces of this plant. The AuNPs were characterised using UV-Vis spectrometry, dynamic light scattering, high resolution – transmission electron microscopy, and in vitro stability testing. A cell viability assay showed that these AuNPs exhibited cytotoxicity towards E0771 cells in a dose-dependent manner, where cells treated with the highest concentration of AuNPs (250 µg/mL) exhibited the lowest cell viability (7%). During the in vivo pilot study, C57BL/6 mice were inoculated with TNBC using the E0771 cells. It was found that TNBC had rapidly spread, resulting in metastasis in the liver, as well as omentum and mesentery. This resulted in a number of mice dying; therefore, shortening treatment time of the AuNPs. It is suggested that AuNP treatment may have exacerbated mouse death by promoting ROS production in metastasised tissue, suggesting that AuNP treatment may not be suitable for stage 4 TNBC. Tumor analysis of caspase-3 content showed that the AuNPs exhibited potential pro-apoptotic activity in the tumours, prompting further research into the tumour uptake and apoptotic mechanism of these AuNPs. , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-12
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