Synthesis of and potentiometric studies with bisphosphonate ligands APDDAM and PolyHEDP as potential carriers of radionuclides : in attempt to develop effective 117MSn radio pharmaceuticals for bone metastases
- Authors: Ranqhai, Tsekiso
- Date: 2014-08-18
- Subjects: Radiochemistry , Bone metastasis - Radiotherapy , Phosphonates , Radioisotopes
- Type: Thesis
- Identifier: uj:12077 , http://hdl.handle.net/10210/11824
- Description: M.Sc. (Chemistry) , Secondary cancer tumour formation, often called metastasis, remains one of the great scientific challenges in public health. Patients with skeletal metastases have a low survival rate, with great discomforts experienced by the sufferers. Pain, decreased mobility, pathologic bone fractures are some of the effects that these patients have to live with. Significant inroads have been made in using radio pharmaceuticals as a pain palliation treatment for bone metastases. They comprise of a bone seeking phosphonate ligand and a radionuclide. The structural variation of the phosphonate affects to a great extend the effectiveness of the radiopharmaceutical with the greatest shortfall being myelosuppression at high doses. In this study an attempt is made at synthesizing novel bisphosphonates, APDDAM and APDDPE. After several synthetic steps from the protected β-alanine tert butyl ester, the free acid precursor was achieved (as shown in the NMR and elemental analysis) in good yields. Unfortunately the final reaction step to form the bisphosphonate ligand was unsuccessful, with the free acid precursor dissociating in the acidic conditions to form salts. A polymer ligand poly-HEDP was synthesized from its free acid form in relatively low yields. The ligand was used in potentiometric studies with the metal ions Ca(II), Mg(II), Cu(II), Zn(II), Sn(II) and Sn(IV) to evaluate its potential as radiopharmaceutical candidate. The ESTA model formation constants obtained were used in the ECCLES blood plasma model to evaluate the competitive stability of the complexes against biological metal ions and ligands. The Sn(IV)-poly-HEDP complex was shown to be unstable, with a 100 % dissociation. On the other hand the Sn(II)-poly-HEDP showed much improved stability with 100 % of the metal ion remaining bound to the ligand.
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- Authors: Ranqhai, Tsekiso
- Date: 2014-08-18
- Subjects: Radiochemistry , Bone metastasis - Radiotherapy , Phosphonates , Radioisotopes
- Type: Thesis
- Identifier: uj:12077 , http://hdl.handle.net/10210/11824
- Description: M.Sc. (Chemistry) , Secondary cancer tumour formation, often called metastasis, remains one of the great scientific challenges in public health. Patients with skeletal metastases have a low survival rate, with great discomforts experienced by the sufferers. Pain, decreased mobility, pathologic bone fractures are some of the effects that these patients have to live with. Significant inroads have been made in using radio pharmaceuticals as a pain palliation treatment for bone metastases. They comprise of a bone seeking phosphonate ligand and a radionuclide. The structural variation of the phosphonate affects to a great extend the effectiveness of the radiopharmaceutical with the greatest shortfall being myelosuppression at high doses. In this study an attempt is made at synthesizing novel bisphosphonates, APDDAM and APDDPE. After several synthetic steps from the protected β-alanine tert butyl ester, the free acid precursor was achieved (as shown in the NMR and elemental analysis) in good yields. Unfortunately the final reaction step to form the bisphosphonate ligand was unsuccessful, with the free acid precursor dissociating in the acidic conditions to form salts. A polymer ligand poly-HEDP was synthesized from its free acid form in relatively low yields. The ligand was used in potentiometric studies with the metal ions Ca(II), Mg(II), Cu(II), Zn(II), Sn(II) and Sn(IV) to evaluate its potential as radiopharmaceutical candidate. The ESTA model formation constants obtained were used in the ECCLES blood plasma model to evaluate the competitive stability of the complexes against biological metal ions and ligands. The Sn(IV)-poly-HEDP complex was shown to be unstable, with a 100 % dissociation. On the other hand the Sn(II)-poly-HEDP showed much improved stability with 100 % of the metal ion remaining bound to the ligand.
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A record of 236U content from 1940 to 2012 in a coral core from Europa Island, Mozambique Channel : implications on the pathways of fallout from bomb tests in the Pacific Ocean
- Senzani, Khangeziwe Karen, Kramers, J.D., Prof., Winkler, S.R., Dr., Ambushe, A., Dr.
- Authors: Senzani, Khangeziwe Karen , Kramers, J.D., Prof. , Winkler, S.R., Dr. , Ambushe, A., Dr.
- Date: 2019
- Subjects: Ocean currents , Radioactive fallout , Radioisotopes
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/418791 , uj:35521
- Description: Abstract: This is a study on the ratios of 236U/238U in a coral core sampled at Europa Island in the southern Mozambique channel, spanning the period from 1940 through 2012. The primary aim of the work was to obtain a record of variations and trends of these ratios in the local sea water and link them to known nuclear bomb tests (mainly in the Pacific Ocean), fallout from which might have reached this region via the prevailing ocean currents, and assess any significant delays which could characterize ocean currents. Values close to 10-9 for the ratio were obtained on the oldest samples from the core, representing the pre-nuclear test era. This is ca. 2 orders of magnitude higher than published values obtained on Caribbean pre-nuclear coral core, and analyses of a prenuclear standard (Vienna KkU) during this work. This indicates some contamination in the chemical sample preparation. Probably due to this high background, no anomalies were observed prior to 1960 although US nuclear tests were carried out in the 1950’s in the Pacific Proving Grounds of the Marshall Islands, and British tests is south Australia. A single very high value (5.94 ×10-7) obtained for 1988 is believed to result from contamination by a hot particle. Disregarding this, the results obtained show two anomalies that are considered real as they rise and fall over several years. .. , M.Sc. (Geology)
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- Authors: Senzani, Khangeziwe Karen , Kramers, J.D., Prof. , Winkler, S.R., Dr. , Ambushe, A., Dr.
- Date: 2019
- Subjects: Ocean currents , Radioactive fallout , Radioisotopes
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/418791 , uj:35521
- Description: Abstract: This is a study on the ratios of 236U/238U in a coral core sampled at Europa Island in the southern Mozambique channel, spanning the period from 1940 through 2012. The primary aim of the work was to obtain a record of variations and trends of these ratios in the local sea water and link them to known nuclear bomb tests (mainly in the Pacific Ocean), fallout from which might have reached this region via the prevailing ocean currents, and assess any significant delays which could characterize ocean currents. Values close to 10-9 for the ratio were obtained on the oldest samples from the core, representing the pre-nuclear test era. This is ca. 2 orders of magnitude higher than published values obtained on Caribbean pre-nuclear coral core, and analyses of a prenuclear standard (Vienna KkU) during this work. This indicates some contamination in the chemical sample preparation. Probably due to this high background, no anomalies were observed prior to 1960 although US nuclear tests were carried out in the 1950’s in the Pacific Proving Grounds of the Marshall Islands, and British tests is south Australia. A single very high value (5.94 ×10-7) obtained for 1988 is believed to result from contamination by a hot particle. Disregarding this, the results obtained show two anomalies that are considered real as they rise and fall over several years. .. , M.Sc. (Geology)
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To study the mobility of the naturally occurring radioactive materials (NORMs) in the sediments as a function of changing environmental conditions
- Authors: Shongwe, Nkosinathi Sipho
- Date: 2015
- Subjects: Radioisotopes , Radiobiology , Acid mine drainage , Liquid scintillation counting
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/58831 , uj:16498
- Description: Abstract: Please refer to full text to view abstract , M.Phil. (Energy Studies)
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- Authors: Shongwe, Nkosinathi Sipho
- Date: 2015
- Subjects: Radioisotopes , Radiobiology , Acid mine drainage , Liquid scintillation counting
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/58831 , uj:16498
- Description: Abstract: Please refer to full text to view abstract , M.Phil. (Energy Studies)
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Chemie in die bereiding, skeiding en gehaltebeheer van draervrye radioisotope en radiofarmaseutiese middels
- Van der Walt, Tjaart Nicolaas
- Authors: Van der Walt, Tjaart Nicolaas
- Date: 2014-06-02
- Subjects: Ion exchange chromatography , Radioisotopes , Radiopharmaceuticals
- Type: Thesis
- Identifier: uj:11330 , http://hdl.handle.net/10210/10922
- Description: M.Sc. (Chemistry) , This thesis describes the preparation of lead-203 and thallium-201 via proton induced nuclear reactions on natural lead cyclotron targets. The separation of bismuth-206, lead-203 and thallium-201 from the lead target material was investigated in this study. Excellent separations, by ion exchange chromatography, were developed to prepare carrier-free bismuth-206, lead-203and thallium-201. The separation of lead-203 and thallium-201 from thallium cyclotron target material was also investigated in this study, and excellent separations, using ion exchange chromatography, were achieved. The development of spectrophotometric methods for the determination of copper and europium in radiopharmaceuticals was investigated and sensitive methods were compiled. The determination of BIDA, DISIDA, DTPA and HOP in 99-Tc· labelled compounds was also studied in this thesis, and indirect spectrophotometric methods were developed. The determination of BIDA and DISIDA in labelling kits was studied and a complexometric titration, with copper as titrant and eriochrome cyanine R as indicator, was developed. The preparation of calciumtrisodium diethyltriaminepentaacetic acid, for use in DTPA labelling kits, and the development of quality control tests on the product were included in this study. A complexometric method was compiled to determine the calcium and DTPA contents of the CaNa3DTPA. Successive titrations of DTPA (with thorium) and calcium (with DCTA) are carried out using the same sample solution; methyl thymol blue is used as indicator.
- Full Text:
- Authors: Van der Walt, Tjaart Nicolaas
- Date: 2014-06-02
- Subjects: Ion exchange chromatography , Radioisotopes , Radiopharmaceuticals
- Type: Thesis
- Identifier: uj:11330 , http://hdl.handle.net/10210/10922
- Description: M.Sc. (Chemistry) , This thesis describes the preparation of lead-203 and thallium-201 via proton induced nuclear reactions on natural lead cyclotron targets. The separation of bismuth-206, lead-203 and thallium-201 from the lead target material was investigated in this study. Excellent separations, by ion exchange chromatography, were developed to prepare carrier-free bismuth-206, lead-203and thallium-201. The separation of lead-203 and thallium-201 from thallium cyclotron target material was also investigated in this study, and excellent separations, using ion exchange chromatography, were achieved. The development of spectrophotometric methods for the determination of copper and europium in radiopharmaceuticals was investigated and sensitive methods were compiled. The determination of BIDA, DISIDA, DTPA and HOP in 99-Tc· labelled compounds was also studied in this thesis, and indirect spectrophotometric methods were developed. The determination of BIDA and DISIDA in labelling kits was studied and a complexometric titration, with copper as titrant and eriochrome cyanine R as indicator, was developed. The preparation of calciumtrisodium diethyltriaminepentaacetic acid, for use in DTPA labelling kits, and the development of quality control tests on the product were included in this study. A complexometric method was compiled to determine the calcium and DTPA contents of the CaNa3DTPA. Successive titrations of DTPA (with thorium) and calcium (with DCTA) are carried out using the same sample solution; methyl thymol blue is used as indicator.
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