The dissertation details the experimental work on the attempt to develop rhenium(V)phthalocyanine complexes directly from its +7 oxidation state (perrhenate). Different reducing agents (PPh3, Na2S2O5 and NaBH4) were employed and consequently, different results were acquired, such as rhenium(V)-mediated oxidative hydrolysis of the phthalocyanines (Pcs), the formation of a rhenium-phthalocyanine complex and phthalocyanine-capped nanoparticles. The rhenium nanoparticles that were formed were optimized from a synthesis point of view and, cancer localizing ability of the rhenium nanoparticles was investigated. The complexes were synthesized through direct metalation of pre-formed metal-free phthalocyanines using the “cold isotopes” of the rhenium metal. Rhenium nanoparticles (Re NPs) were synthesized in aqueous saline medium so as to imitate the environment on which Re is produced from its reactor. The nanoparticles (NPs) were capped with phthalocyanines which were covalently biofunctionalized with a folic acid moiety to enhance the targeting ability of the Re NPs. These NP systems were characterised with techniques such as ultraviolet-visible UV-Vis spectroscopy and transmission electron microscopy TEM. Cytotoxicity of the NPs was tested against four different cell lines and subsequently their cytotoxicity profiles were elucidated, and the profiles shown a dose-dependent responsealthough the results in some cell lines were unclear. Their fluorescence properties were also studied to provide photophysical information for investigation of their tumor localization using human cancer cells lines via confocal fluorescence microscopy studies. Particle size effect on localization of NPs was also investigated using confocal fluorescence and TEM. Two sizes were chosen (10 and 50 nm), and the smaller NPs (10 nm) were found to exhibit stronger fluorescence properties than the 50 nm NPs, and they were also found to have a better localization ability than the 50 nm NPs. Finally, their tumor and organ biodistribution studies will be carried out using micro-SPECT kits and model mice (using the “hot” isotopes in a radiopharmacy laboratory).

MESHWR / Department of Hydrology and Water Resources / This research involves the investigation of the interaction of different sized Nano Gold particles released into municipal drinking water and municipal waste water. Waste water was collected from Malamulele waste water treatment plant and the municipal water was collected at Mintek in Johannesburg, Randburg, South Africa. The waste water was analysed using ICP-MS to detect the metals and anions in it. The results showed the abundance of Sulphur (464 ppm), Calcium (28 ppm), Chloride (27.8 ppm), Iron (20 ppm), Magnesium (8.2 ppm), silicon (6.192 ppm) in descending order and other trace elements, including gold, that were immeasurable (<0.1). The simulated situation was created by adding 20nm gold and 40nm gold nanoparticles into municipal drinking water and waste water and kept at different environmental conditions (light, light and agitation, dark, dark and agitation) under aerobic and anaerobic conditions over a period of two months. Physico-chemical properties (pH and chemical oxygen demand) of the solutions were checked once in a month. The pH fluctuated between the acceptable ranges (5.5 – 9.5) for the two month period. Both municipal water and waste water, with and without gold nanoparticles, under aerobic condition showed an increase in chemical oxygen demand. The gold content in waste water under anaerobic condition showed an increase while under aerobic condition the decline in gold content was evident. The zeta potential of gold nanoparticles in waste water in light and agitation showed (-30 mV) while waste water on other environmental condition (light, dark and dark with agitation) presenting unstable (-18 mV) charge, but the charge shifted positively on the second month rendering them also unstable. Dynamic light scattering and TEM were used to check any possible aggregation or agglomeration of nanoparticles in the waste water. There were some few discrepancies where TEM and DLS contradict, but overall there was no significant probability of any aggregation of gold nanoparticles. The EDX was used to confirm the presence of Au0 in the waste water (with added gold nanoparticles). The research did show that the gold nanoparticles would exist as Au0 in the waste water and thus the discharge of Au-NPs to the sewer system is not recommended, but rather recycle them.