Showing items 1 - 14 of 14

Your selections:

An electrochemical urea biosensor on a carbon nanofiber-poly (amidoamine) dendrimer supramolecular-platform

- Blessie, Wessel

  • Authors: Blessie, Wessel
  • Date: 2020
  • Subjects: Supramolecular electrochemistry , Nanomedicine , Polymeric composites , Carbon composites
  • Language: English
  • Type: Masters (Thesis)
  • Identifier: http://hdl.handle.net/10210/473889 , uj:42696
  • Description: Abstract: The concentration of urea in serum or urine in human body should be in moderate levels (3.3–6.7 mM). The elevation of urea above the normal level indicates gastrointestinal bleeding, obstruction of the urinary tract, burns, shock, or renal failure. The decline in the concentration of urea below moderate levels causes cachexia, hepatic failure, and nephritic syndrome. The increase/decrease in the concentration of urea poses health risks. Thus, it is essential to determine the urea concentration for early diagnosis of kidney related disease. In this mini-dissertation, we report a novel amperometric urea biosensor based on the immobilisation of urease enzyme on carbon nanofiber-generation 3 polyamidoamine dendrimer immobilisation layer on a glassy carbon electrode (GCE). Electrospun polyacrylonitrile (PAN) based carbon nanofibers were obtained with an average diameter of 132 nm through stabilization, electrospinning, and carbonization of polyacrylonitrile (PAN) polymer. The structure and the morphology of the PAN carbon nanofibers were studied by High Resolution Transmission Electron Microscope (HR-TEM) and Field Emission Scanning Electron Microscope (FE-SEM)... , M.Sc. (Nanoscience)
  • Full Text:

Characterization, in vitro cytotoxicity studies and photoactive effect of gold nanorods on colorectal cancer cells

- Kadanyo, Sania

  • Authors: Kadanyo, Sania
  • Date: 2016
  • Subjects: Nanostructured materials , Rectum - Cancer - Treatment , Cancer - Treatment , Nanomedicine
  • Language: English
  • Type: Masters (Thesis)
  • Identifier: http://hdl.handle.net/10210/124772 , uj:20958
  • Description: Abstract: Cancer is a disease formed from abnormal growth of cells affecting any part of the body. It is reported that cancer is the third leading cause of death after stroke and heart disease in developed countries. Colorectal cancer (CRC) incidence and mortality rates vary markedly around the world; according to the World Health Organization (WHO) colorectal cancer is the third most commonly diagnosed cancer as well as being the third leading cause of cancer death after lung and gastric cancer worldwide in both sexes. Thus each year over 1 million new patients develop colorectal cancer and over 600,000 patients die from it. The main problem in using most conventional cancer therapies such as anticancer drugs (chemotherapy); as well as radiation is their low selectivity for cancer cells coupled with their often high toxicity to non-targeted cells in the body and they often cause side effects that may be more unbearable than the disease at that particular point in time. In contrast with conventional cancer therapy’s photodynamic therapy (PDT) was developed to try and address the disadvantages caused by conventional therapy’s. Photodynamic therapy is a non-invasive method which yields satisfactory clinical results with fewer adverse side effects accompanied by higher selectivity. Although photodynamic therapy has significantly improved the quality of life and life expectancy of patients with cancer, further advances in therapeutic efficacy are required to overcome numerous side effects for example hydrophobicity and poor selectivity between deceased cells and healthy cells related to conventional PDT. Much attention has been directed to improving photosensitizers. Due to the highly desirable and tunable optical properties of light sensitive nanoparticles they are deemed resourceful in developing phototherapeutic agents for cancer therapy. Gold nanorods (GNRs) showing a surface plasmon resonance (SPR) band at the near infra-red (NIR) region are of great interest for the development of nanomedicine in particular phototherapy of cancer and drug delivery. The main concerns usually encountered when using metal nanoparticles for general bio-applications are their potential toxicity and biological interactions of the nanoparticles with the cells... , M.Sc. (Nanoscience)
  • Full Text:

Evaluation of cell damage induced by irradiated Zinc-Phthalocyanine-gold dendrimeric nanoparticles in a breast cancer cell line

- Mfouo-Tynga, Ivan, Houreld, Nicolette Nadene, Abrahamse, Heidi

Exploring and understanding the catalytic potential of phosphabicyclononane ligands in palladium catalysed cross coupling reactions

- Masanabo, Ntombenhle

  • Authors: Masanabo, Ntombenhle
  • Date: 2020
  • Subjects: Nanostructured materials , Nanomedicine , Ligands , Phosphine
  • Language: English
  • Type: Masters (Thesis)
  • Identifier: http://hdl.handle.net/10210/474076 , uj:42719
  • Description: Abstract: Electron-rich bulky phosphine forms the most effective Pd catalyst systems for cross coupling reactions as they enhance the rate determining step of the catalytic cycle. The quest for an affordable and efficient ligand, prompted the implementation of tertiary bicylic phosphine ligands (Phoban family) in Pd-catalysed cross coupling reactions. Phoban (isomers mixture phosphabicyclo[3.3.1]nonane and phosphabicyclo[4.2.1]nonane) ligand is derived from cis, cis-1,5-cyclooctadiene and considered to be good electron donors, sterically bulk and have an unsymmetrical geometry to assist with an active catalytic system. Catalytic efficiency of phoban was investigated in Suzuki-Miyaura and Heck- Mizoroki cross coupling reactions, and the outcome of the study after an extensive optimisation study of various reaction parameters showed that palladium catalysts derived from 9-eicosyl-9-phosphabicyclononane (L2) gave superior results. This ligand L2 has also been demonstrated by SASOL R & D to be an excellent ligand in Co-catalysed hydroformylation reactions. The results obtained in this study have illustrated that this ligand L2 can facilitate couplings of a wide range of electronically diverse aryl bromides and chlorides with various coupling partners in Suzuki and Heck reactions. The implementation of 9-eicosyl-9-phosphabicyclononane in Heck and Suzuki reactions, provided the desired coupled products in 30-90% yields. In addition, this novel palladium catalyst derived from phoban was applied in the synthesis of industrial important products. The efficacy of this novel catalyst in Suzuki reaction was demonstrated in the synthesis of Felbinac (an anti-inflammatory drug under the trade name Traxam) and OTBN (an anti-hypertensive drug intermediate). Similarly, the success of the new protocol in Heck reaction was exemplified in the synthesis of octinoxate (trade names: Eusolex 2292 and Uvinul MC80; UV absorbers or filters), raspberry ketone derivatives (4-phenyl-2-butanone and 4-(4-methoxyphenyl)-2-butanone) used as flavourants. These products were successfully synthesised in yields ranging from 51 to 94% (GC). , M.Sc. (Chemistry)
  • Full Text:

Hybrid inorganic-organic core-shell nanodrug systems in targeted photodynamic therapy of cancer

- Matlou, Gauta Gold, Abrahamse, Heidi

  • Authors: Matlou, Gauta Gold , Abrahamse, Heidi
  • Date: 2021
  • Subjects: Nanomedicine , Targeted photodynamic therapy , Core shell structure
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/489519 , uj:44637 , Citation: Matlou, G.G.; Abrahamse, H. Hybrid Inorganic-Organic Core-Shell Nanodrug Systems in Targeted Photodynamic Therapy of Cancer. Pharmaceutics 2021, 13, 1773. https://doi.org/10.3390/ pharmaceutics13111773
  • Description: Abstract: Hybrid inorganic-organic core-shell nanoparticles (CSNPs) are an emerging paradigm of nanodrug carriers in the targeted photodynamic therapy (TPDT) of cancer. Typically, metallic cores and organic polymer shells are used due to their submicron sizes and high surface to volume ratio of the metallic nanoparticles (NPs), combined with enhances solubility, stability, and absorption sites of the organic polymer shell. As such, the high loading capacity of therapeutic agents such as cancer specific ligands and photosensitizer (PS) agents is achieved with desired colloidal stability, drug circulation, and subcellular localization of the PS agents at the cancer site. This review highlights the synthesis methods, characterization techniques, and applications of hybrid inorganic-organic CSNPs as loading platforms of therapeutic agents for use in TPDT. In addition, cell death pathways and the mechanisms of action that hybrid inorganic-organic core-shell nanodrug systems follow in TPDT are also reviewed. Nanodrug systems with cancer specific properties are able to localize within the solid tumor through the enhanced permeability effect (EPR) and bind with affinity to receptors on the cancer cell surfaces, thus improving the efficacy of short-lived cytotoxic singlet oxygen. This ability by nanodrug systems together with their mechanism of action during cell death forms the core basis of this review and will be discussed with an overview of successful strategies that have been reported in the literature.
  • Full Text:

Investigation of nano immunotherapy drug delivery in metastatic melanoma cancer cells

- Naidoo, Channay

  • Authors: Naidoo, Channay
  • Date: 2019
  • Subjects: Nanomedicine , Photosensitizing compounds , Drug delivery systems , Melanoma - Chemotherapy
  • Language: English
  • Type: Masters (Thesis)
  • Identifier: http://hdl.handle.net/10210/296670 , uj:32326
  • Description: M.Tech. (Biomedical Technology) , Abstract: Cancer is a disease that is generally caused by environmental factors that cause mutations in the genes and result in cells proliferating abnormally at a rapid pace (Martin et al., 2013). Due to the amount of new cases diagnosed annually, it is one of the most predominant health threats to individuals (Miller et al., 2016). There are multiple treatments available, however due to the severe side effects suffered by patients; alternative forms of treatment therapies require investigation (DeSantis et al., 2014). In 2016 the World Health Organization reported that the incidence of skin cancer is on the rise due to the excessive Ultraviolet (UV) rays’ individuals are being exposed to and that metastatic melanoma is the deadliest form of skin cancer (Swavey et al., 2013). Metastatic melanoma begins in the epidermis where it progresses to other organs (Swavey et al., 2013). Due to this malignancy the limited treatment options that are available are largely ineffective (Seifried et al., 2015). Once metastasis occurs it is difficult to locate where it originated from, can become life threatening if left untreated but frequently redevelops after treatments such as surgery owning to the fact that the primary or secondary site of the tumour was not removed (Allen, 2013). The incidence and mortality rate are continuously increasing because of the metastatic potential of melanoma, suggesting that novel therapies should be proposed which actively target the sites of the tumours (Kunte et al., 2017). Photodynamic therapy (PDT) is an alternative therapy that utilises a photosensitizer (PS) drug, that is taken up by the cell and localised in organelles such as the nucleus, rough endoplasmic reticulum and possibly the mitochondrion (Agostinis et al., 2011; Mroz et al., 2011). The localized PS drug is then activated by laser light at a specific wavelength to yield reactive oxygen species (ROS) which induce cell death modes such apoptosis, necrosis and/or autophagy causing tumour destruction (Agostinis et al., 2011; Maiuri et al., 2007). Thus, PDT is a promising treatment modality that is being investigated in the field of dermatology (Wang et al., 2017). There have been many clinical trials that have been conducted using PDT, however these studies have been done on various other types of skin cancer that...
  • Full Text:

Piperidinylphosphine ligands in palladium-catalyzed cross-coupling reactions

- Lekgau, R. Denise

Potential cytotoxicity and photoactive effect of gold nanorods onto colorectal cancer cells

- Kadanyo, S., Abrahamse, H., Mishra, A.K.

  • Authors: Kadanyo, S. , Abrahamse, H. , Mishra, A.K.
  • Date: 2016
  • Subjects: Nanomedicine , Gold nanorods , Cytotoxicity
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/214792 , uj:21325 , Citation: Kadanyo, S., Abrahamse, H. & Mishra, A.K. 2016. Potential cytotoxicity and photoactive effect of gold nanorods onto colorectal cancer cells.
  • Description: Abstract: Cancer is still one of the main death causes worldwide. Recently the use of nanotechnology in nanobiomedicine is considered as one of the most promising research applications, nanotechnology is providing an exceptional opportunity to improve the treatment of various diseases particularly cancer. This is highly due to the unique chemical and physical properties that are observed at the nanoscale. Gold nanorods (GNRs) in specific show a surface plasmon resonance (SPR) band at the near infra-red (NIR) region for this reason they have been widely studied in biomedical research and are of great interest for the development of nanomedicine precisely phototherapy of cancer and drug delivery. The goal of the current study was to investigate the stability of GNRs in biological media and subsequently assesse their cytotoxic properties and photo killing ability on colorectal cancer (CaCo-2) cells. In this study The GNRs were firstly characterised by, Zeta potential (ζ-potential), ultraviolet–visible (UV–Vis) spectroscopy, and transmission electron microscopy (TEM). The potential cytotoxic effects of the GNRs onto CaCo-2 cell lines were assessed using inverted light microscopy for morphological changes, Trypan blue exclusion assay and (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) for viability, adenosine triphosphate luminescence and cell impedance studies for proliferation, and lactate dehydrogenase membrane integrity assay for potential cell damage. The characterisation results showed that the physicochemical properties of the GNRs in Dulbecco's Modified Eagle's medium (DMEM) were maintained when compared to GNRs suspended in DI water. The GNRs showed a slight increase in size through aggregation but retained their charge. Upon Irradiation at a wavelength of 660 nm, GNRs decreased cell viability and proliferation, increased cell damage. In conclusion, this work clearly demonstrates that GNRs activated at 660 nm significantly increase cytotoxicity induced in CaCo-2 cells.
  • Full Text:

Synthesis and photothermal application of high aspect ratio gold nanorods

- Oladipo, Adewale Odunayo

  • Authors: Oladipo, Adewale Odunayo
  • Date: 2017
  • Subjects: Nanostructured materials , Cancer - Treatment , Cancer invasiveness , Metastasis , Nanomedicine
  • Language: English
  • Type: Masters (Thesis)
  • Identifier: http://hdl.handle.net/10210/244083 , uj:25239
  • Description: M.Sc. (Chemistry) , Abstract: Gold nanorods (Au-NRs) are of great interest in many areas of science and technology owing to their versatility, optical and electronic properties. A very interesting property of Au-NRs is their ability to generate surface plasmon resonance in the near infrared region. This surface plasmon can be enhanced by increasing the aspect ratio of the Au-NRs and can be used for photo-thermal application. While there are simple synthetic methods that allow for shape control and aspect ratio of the Au-NRs, the synthesis of high aspect ratio Au-NRs still proved difficult and often associated with high surfactant concentration, sensitivity to reactants, and reproducibility problems. This study elucidates simplistic ways to synthesize high aspect ratio Au-NRs and their photo-thermal therapy application. High aspect ratio Au-NRs were prepared via a modified seed-mediated synthetic two-pot growth method. Several experimental conditions were altered to investigate their influence on the synthesis of the Au-NRs. The Au-NRs were functionalized using both ligand exchange (PAu-NRs) and gelatin over-coating (gelatin@Au-NRs) strategy to make them more biocompatible. The biological stability, cellular viability, antibacterial activity, and photo-thermal properties were investigated. In vivo photo-thermal therapeutic applications using functionalized PAu-NRs under NIR laser irradiation with a temperature cooling system was also assessed in a mouse model. The PAu-NRs was delivered to the metastatic tumor-bearing lymph node using the lymphatic delivery administration route. The anti-tumor effect of the treatment procedure was evaluated using an in vivo bioluminescence imaging system (IVIS), 3D high frequency ultrasound (VEVO) and histological analysis. The study shows that by using lower seed volume, lower pH and lower surfactants concentration, high aspect ratio Au-NRs can be synthesized with high reproducibility. In addition, the aging of reactants was found to influence the reproducibility of the Au-NRs. For the photo-thermal application, this route led to sufficient accumulation of the anti-cancer agent in the metastatic site within a short time. The delivery route afforded precise control over the treatment time and treatment conditions. The results showed complete tumour ablation and growth termination with no growth reoccurrence after the treatment. This research presents an alternative, non-invasive therapeutic protocol in the treatment of cancer metastasis.
  • Full Text:

Synthesis of zinc phthalocyanine-gold nanoparticles conjugated compounds and determination of photodynamic effects in a breast cancer cell line

- Mfouo-Tynga, Ivan Sosthene

  • Authors: Mfouo-Tynga, Ivan Sosthene
  • Date: 2017
  • Subjects: Breast - Cancer - Photochemotherapy , Nanomedicine
  • Language: English
  • Type: Doctoral (Thesis)
  • Identifier: http://hdl.handle.net/10210/226525 , uj:22905
  • Description: D.Tech. (Biomedical Technology) , Abstract: Cancer is a disease that occurs following mutations in the genes, which control cell growth. These mutations are caused by different causes and viral infections are among those. Cancer cells can conquer other cells and tissues causing changes to their deoxyribonucleic acids (DNA). Cancer appears almost incurable once it has started to metastasize and invade other body organs. At that stage, any therapeutic intervention was believed to cause more harm than curative effects (Gallucci, 1985; Kardinal and Yarbro, 1979). Late diagnosis and treatment reduces the possibility of an effective cure (He et al., 2007). The development of a malignant tumour from cells in the breast is known as breast cancer. Breast cancer is generally initiated in the stromal cells, which are fibrous and fatty tissues, or in the glandular cells; which produce breast milk (American Cancer Society, 2014). Breast cancer is the leading cancer among women and cause of cancer death worldwide (Ferlay et al., 2008). It is a heterogeneous disease with several markers, which are essential for diagnosis and include the estrogen receptors (ER), progesterone receptors (PR) and human epidermal growth factor receptor 2 (HER-2) (Mosoyan et al., 2013; Yang et al., 2013). Like all cancer, breast cancer can be cured if diagnosed at an early stage. Treatment of cancer has evolved from palliative therapies to conventional therapies, which consist of surgery, hormonal therapy, radiation therapy, immunotherapy, chemotherapy, and adjuvant therapy. (Gallucci, 1985; Kardinal and Yarbro, 1979). Photodynamic therapy (PDT) has become popular as an alternative cancer treatment modality. PDT depends on molecular oxygen and photodynamic action for effective cancer destruction (Von Tappeiner and Jesionek, 1903; Von Tappeiner and Joblauer, 1904). Today, PDT is designated as a chronological and minimally invasive cancer therapy with numerous benefits over conventional treatments. The initial step of this therapy consists of the administration of drugs to patients,..
  • Full Text:

Synthesis, characterization and cytotoxic activity of gold nanoparticles using natural occurring flavonoids

- Nemandava, Livhuwani

  • Authors: Nemandava, Livhuwani
  • Date: 2017
  • Subjects: Flavonoids , Nanostructured materials , Nanomedicine , Gold , Flavonoids - Therapeutic use
  • Language: English
  • Type: Masters (Thesis)
  • Identifier: http://hdl.handle.net/10210/243968 , uj:25224
  • Description: M.Sc. (Nanoscience) , Abstract: Plant phytochemicals have been under extensive research because of their preferable properties. Phytochemicals are phenolic compounds which may vary structurally which distinguish their intended applications. They possess anti-oxidant activities which have been a good requirement for treatment against certain ailments which include cancer. The anti-oxidant properties of phytochemicals are capable of relieving stress from cells by scavenging on reactive oxygen species or free radicals. The use of antioxidants has been in use for decades since it is in the human diet, hence extraction of these compounds for medical applications may be ideal since no significant side effects have been reported upon normal consumption. The effectiveness of anti-oxidants possessed by plant phytochemicals depends on the type of phytochemicals, their structural composition and the concentration. Research has uncovered the use of anti-oxidants as reducing agents for the synthesis of metallic nanoparticles for various applications. The synthesis has been found to be cost effective and amenable to optimization for preferred applications. This study describes the synthesis of gold nanoparticles by flavonoids; Sigmoidin A, Sigmoidin B isolated from Erythrina species and Durmillone isolated from Griffoniana species. The natural compounds have been fully characterized by UV-Vis, NMR and FT-IR. The compounds and their relative synthesized AUNPs were tested for anti-cancer activities against Normal Kidney Fibroblasts (BHK 21) and colorectal carcinoma (HCT 116) cell line. A modified tuckervich method was used to synthesize AuNPs which were further characterized by UV-Vis, DLS, TEM, EDX and FT-IR. The synthesis was successful as was observed by a colour change of chloroauric solution from golden yellow to pink-wine red colours. The assumed presence of AuNPs in solution was determined by UV-Vis which measured 595.9nm for Sigmoidin A, 554.5nm for Sigmoidin B and 531nm for Durmillone. These maximum wavelengths of absorption by the AuNPs synthesized by all three flavonoids are characteristic of AuNPs as reported by literature. Average particle size, dispersity and zeta potential values of the synthesized AuNPs were determined by DLS. Properties of Sigmoidin A-AuNPs as per DLS results were 0.143 PDI, 64.8 d.nm and 0.170 mV which mean that the AuNPs were not aggregated but not stable as per the zeta potential value. Sigmoidin B-AuNPs properties by DLS were 0.443 Pdi, 34.4 d.nm and -0.0772 mV which meant that the nanoparticles were monodispersed but not stable as per the zeta-potential. Durmillone-AuNPs properties were 0.153 PDI, 32.7 d.nm and 0.0549 mV which...
  • Full Text:

The development of electrochemical aptamer biosensors based on polyamidoamine dendrimer-streptavidin supramolecular architecture

- Soda, Narshone

  • Authors: Soda, Narshone
  • Date: 2017
  • Subjects: Supramolecular electrochemistry , Molecular structure , Nanomedicine
  • Language: English
  • Type: Masters (Thesis)
  • Identifier: http://hdl.handle.net/10210/235917 , uj:24136
  • Description: M.Tech. (Chemistry) , Abstract: This dissertation reports on the development of an electrochemical aptasensor for hydrogen peroxide and thrombin based on a novel polyamidoamine dendrimer-streptavidin supramolecular architecture. Polyamidoamine dendrimer (PAMAM) was electrodeposited on a glassy carbon electrode using cyclic voltammetry at a potential window of -200 mV to +1100 mV at scan rate 50 mV s-1. The electrode was labelled GCE/PAMAM. A 50 μL volume of 100 μg/mL streptavidin (strept) was drop coated on the GCE/PAMAM electrode for 2 h. The electrode was labelled GCE/PAMAM/Strept and also referred to as the supramolecular platform. The platform was characterised using various techniques such as voltammetry, electrochemical impedance spectroscopy, electron microscopy etc. The supramolecular architecture (GCE, PAMAM)/ strept) was conjugated to an enzyme called horseradish peroxidase (HRP) to make the biosensor GCE/PAMAM/Strept-HRP. The biosensor i.e. GCE/PAMAM/Strept-HRP was used for the detection of hydrogen peroxide. The GCE/PAMAM/Strept-HRP biosensor was studied using electrochemical techniques (CV, SWV, EIS and chronoamperometry) and microscopic techniques (HR-SEM). The platform was conducting and electroactive exhibiting reversible electrochemistry (E°′ = 450 mV and Ipa/Ipc ≈ 1 in Fe(CN)63-/4-). The second part of the work involves the detection of thrombin using a GCE/PAMAM/Strept/TBA modified electrode. Biotinylated aptamer probe was immobilised on the platform through biotin-streptavidin interaction. The aptasensor was monitored using CV, SWV and EIS. The selectivity of the GCE/PAMAM/Strept/TBA based aptasensor was evaluated using interfering proteins of BSA, lysozyme, and haemoglobin that also co-exist with thrombin in the blood. The relative response obtained shows insignificant effect for the interfering proteins with BSA and haemoglobin having a relative response of 9.2% and 7.6% respectively. This confirms the excellent specificity of the proposed aptasensor.
  • Full Text:

The effects of succussion on nanoparticles in ferrum metallicum 30C

- Hobson, Deborah Dawn

  • Authors: Hobson, Deborah Dawn
  • Date: 2019
  • Subjects: Homeopathic pharmacy , Nanoparticles , Nanostructured materials , Nanomedicine , Homeopathy
  • Language: English
  • Type: Masters (Thesis)
  • Identifier: http://hdl.handle.net/10210/399657 , uj:33319
  • Description: Abstract : Nanoparticles are microscopic materials which range in length from 1-100 nanometres (nm). Nanoparticles have unique properties due to their size and shape, which include an increase in surface area, surface reactivity, thermal energy and diffusion rate. Nanomedicine refers to the application of nanoparticles in medicine, particularly in diagnostic techniques and as drug delivery systems. Nanoparticles are ideal for this as they provide greater bioavailability, are more easily absorbed by the body and produce a therapeutic effect with fewer side effects. Laboratory techniques to create nanoparticles include the top-down and bottom-up methods. Within these two methods are various synthesis techniques for creating nanoparticles, including solid phase synthesis, liquid phase synthesis, gas phase synthesis and green synthesis. Homoeopathy uses the top-down method by physically breaking down the starting substance via the process of potentization. Homoeopathy is a branch of complementary medicine (CM) founded by Dr Samuel Hahnemann in the late 1700’s. It is based on the principle similia similibus curantur, which translates to ‘like cures like’. Homoeopathic remedies are highly diluted substances which retain minute particles of the starting substance in the form of nanoparticles. The method used to make homoeopathic remedies is referred to as ‘potentization’ and includes trituration (grinding and serial dilution) of solid substances and succussion (violent shaking) of liquid substances. However, while homoeopathy has set guidelines for the trituration part of potentization, it lacks standardisation regarding the number of succussions which should be used. Iron (Fe) is a highly reactive silvery-white metal that easily forms compounds and alloys with other metals and has unique ferromagnetic properties which are stronger at lower temperatures. Ferrum metallicum, the homoeopathic remedy made from iron, can be used for a wide range of conditions when prepared in homoeopathic form. The aim of this study was to investigate the effect of succussion on the presence, size and distribution of nanoparticles in Ferrum metallicum 30C, when prepared with 0, 10 or 100 succussions, using transmission electron microscopy (TEM). iv This was a quantitative, experimental study performed at the Department of Chemistry, at the University of Johannesburg. Three batches of Ferrum metallicum 30C, with 0, 10 and 100 succussions respectively, and three controls of 43% ethanol with 0, 10 and 100 succussions respectively, were manufactured by the researcher. This was done at the laboratory of a registered manufacturer of homoeopathic medicines in Johannesburg. The researcher underwent training on the use of each of the laboratory analysis techniques. The sample preparation, experimental design and analysis of the samples was conducted by the researcher, under supervision and help of the laboratory technicians. Transmission Electron Microscopy (TEM) was conducted on two batches of samples. The first batch of samples showed contamination of the ethanol used to manufacture the test and control samples. The test samples were therefore manufactured a second time and TEM analysis conducted again. Additional analysis techniques were used to determine whether the first batch of test and control samples were contaminated and how the contamination had occurred. These analysis techniques included Energy Dispersive Spectroscopy (EDS), Inductively Couples Plasma Emission Spectroscopy (ICP-OES), Dynamic Light Scattering (DLS). An analysis for zeta potential of the samples and controls was conducted to explain the agglomeration of particles. TEM photographs were analysed by the researcher, under guidance of the co-supervisor, using the computer programme ImageJ. The results for EDS, ICP-OES, DLS and Zeta Potential were generated by the built-in software of the analysis machines, either as graphs or as numerical values. These were then analysed by the researcher under the guidance of the laboratory technicians. A total of five experimental procedures were conducted. The results of the experiments showed that the first batch of test and control samples was contaminated as the ethanol used to manufacture the samples contained traces of iron and unidentified particles. The additional analysis techniques helped confirm the contamination, and it was discovered that purified water, which was used to manufacture the ethanol used in the study, is not completely free of particles. The second batch of test and control samples, manufactured with distilled water, which is almost completely particle-free, showed positive results. The presence of spherically-shaped iron nanoparticles was confirmed for the test samples. Batch 1, Samples 1 and 2 (Ferrum v metallicum 30C with 0 and 10 succussions respectively), contained nanoparticles which were evenly distributed and unagglomerated. Batch 1, Sample 3 (Ferrum metallicum 30C with 100 succussions) had nanoparticles which were smaller in size, greater in number and agglomerated. Batch 2, Samples 1-2 (Ferrum metallicum 30C with 0 and 10 succussions respectively) contained nanoparticles which were more defined in shape, with similar numbers and sizes, and existed mainly as well-distributed, unagglomerated nanoparticles. Batch 2, Sample 3 (Ferrum metallicum 30C with 100 succussions) had nanoparticles which were slightly less in number and smaller, according to the automatic analysis by ImageJ, and which appeared to be distributed unevenly in smaller clusters. The first batch of control samples contained a large number of unidentified particles. The second batch of control samples also contained particles, although significantly less than the first batch of controls. Overall, the experiments showed that the number of succussions given does affect the number, size and distribution of nanoparticles in a homoeopathic remedy. The results of this experiment help to support the current research on nanoparticles in homoeopathic remedies and help to explain the effect of succussion on the nanoparticles within the remedies. , M.Tech. (Homoeopathy)
  • Full Text:

Towards HIV sensing : the development of electrochemical DNA/RNA aptamer biosensors on dendrimer-gold platforms

- Vivian, John Suru

  • Authors: Vivian, John Suru
  • Date: 2013-07-30
  • Subjects: HIV infections - Diagnosis , Biosensors , Electrochemical sensors , Nanomedicine , Nanostructured materials , Dendrimers , Gold
  • Type: Thesis
  • Identifier: uj:7716 , http://hdl.handle.net/10210/8580
  • Description: M.Sc. (Chemistry) , With the increase in the number of new Human Immunodeficiency Virus (HIV) infection and mortality rate worldwide partly due to diagnostic drawbacks which gives false negatives during the window period, it is imperative to find an alternative method of detection. The need for prompt, bed-side and field applicable analytical devices for biomedical purposes cannot be over emphasized in our fast paced world today. As a contribution to meeting these challenges, this dissertation reports (i) the development of novel electrochemical DNA/RNA aptamer biosensor for HIV sensing and (ii) the development of other DNA sequence specific electrochemical biosensors. These biosensors were based on composite platforms of dendrimer and gold nanoparticles...
  • Full Text:
  • 1
  • Disclaimer
  • Privacy
  • Copyright
  • Contact