A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, in fulfillment of the requirements for the degree of Doctor of Philosophy / Alzheimer’s disease (AD) is the most prevalent and progressive neurodegenerative disorder (ND). It is characterized by a progressive decline of cognitive function, complete loss of memory, deterioration of visual capacity and the inability to function independently. According to the World Health Organization (WHO) it is estimated that about 26 million people suffer with AD worldwide. Although the etiology of AD is not fully understood, the aggregation of β-amyloidal (A) peptides that are associated with the formation of extracellular neurotoxin senile plaques and neurofibrillary tangles comprising hyperphosphorylated tau proteins have been recognized as the primary constituents that play a crucial role in AD. Several potential neurotherapeutic agents that can improve the management of AD such as metal chelators and alkaloid drugs have been approved by the US Food and Drug Administration (FDA) and European Medicines Agency (EMA). Metal chelators [e.g. histidine, Ethylenediaminetetraacetic acid (EDTA) and zinc acetate (ZnAc)] are the main therapy used for modulating Aβ peptide aggregation with biological metals (such as zinc and copper ions) which is associated with promoting neurotoxicity in AD. While alkaloid drugs, such as donepezil, galantamine and rivastigmine, are used to inhibit the enzyme acetylcholinesterase (AChE); memantine is used to block the N-methyl-D-aspartate (NMDA) receptors associated with pathological activation. Despite the availability of these indispensable drugs, the clinical utility of these drugs is hampered by their poor retention and difficulty in bypassing the highly restrictive Blood Brain Barrier (BBB). Therefore this study aimed at developing novel nanoliposomes (NLPs) surface-engineered with chelating and synthetic peptides that are capable of crossing the BBB thus improving delivery efficacy and modulating the extracellular neurotoxicity associated with β-Amyloid aggregates of AD. Furthermore, since this system was designed for a chronic condition, a temporary depot-based polymeric system was integrated for further enhancement of the liposomal half-life, storage and prolonged drug delivery over a period of 50 days. The surface-engineered NLPs produced were spherical in shape, 100-149±28nm ~ size, with a zeta potential range of -9.59 to -37.3mV and a polydispersity index (PdI) of 0.02-0.2. A Box-Behnken experimental design was employed for maximizing the ligand coupling efficiency (40-78%) and drug entrapment efficiency (DEE) that ranged from 42-79%. The optimized peptide-based ligand NLP formulation showed sustained drug release (30% of drug released within 48 hours). Chelating ligands on the surface of NLPs showed 50-68% modulation of neurotoxicity on PC12 neuronal cells induced by ZnAβ (1-42) or CuAβ (1-42) aggregates. When drug-loaded functionalized NLPs were embedded within the temporal hydrophilic hydrogel network/scaffold as an implantable nano-enabled bio-robotic intracranial device (BICD), the physicomechanical and physicochemical dynamics showed improvement of liposomal structure such as the stability, and homogeneity in distribution of the liposomes within the internal core of the hydrogel networks and post-lyophilized scaffold. In vitro studies in simulated cerebrospinal fluid (CSF) showed prolonged release behavior of the drug-loaded functionalized NLPs from the BICD with 50-70% released over 50 days. Scanning Electron Microscopy (SEM) and confocal microscopy confirmed intact liposomal structures within the temporal polymeric scaffold/depot post-fixation and post-lyophilization. Ex vivo studies confirmed cell proliferation and a low level of lactate dehydrogenase (LDH), which is associated with cell membrane damage/injury, after PC12 neuronal cells were exposed to the BICD. In addition, when PC12 neuronal cells were exposed to the BICD high accumulation of galantamine (GAL) into these PC12 neuronal cells was observed post-cultivation. This outcome indicated that the released drug-loaded functionalized NLPs from the BICD were still in their intact form and capable of serving as bio-robotic markers for the delivery of GAL into the neuronal cells in response to AD. Furthermore, intracellular activity validated that the synthetic peptide has the potency for targeted delivery of the drug-loaded NLPs post-release of the BICD in ex vivo studies. Overall, results from this study revealed that the BICD device had superior cytocompatibility and may be suitable for application as a prolonged and targeted delivery system for GAL into neuronal cells to treat AD.

M. Pharm., Faculty of Health Sciences, University of the Witwatersrand, 2009 / Parkinson's disease, primarily defined as the depletion of dopaminergic neurons in the subtantia nigra of the brain, gives rise to severely debilitating motor symptoms. The pharmacological gold standard treatment for the disease, Levodopa , holds great limitations yet still remains the most effective treatment for the disease for the last 40 years. There has been research into novel drug delivery systems for the treatment of the disease that include the development of implantable devices however none have been introduced onto the market. As the neurodegenerative disorder ravages the younger-aged population so the urgency for the effective chronic treatment of the disease escalates. The field of nanotechnology brings promise for the targeted delivery of drugs which is highly sought after in the treatment of central nervous system disorders. A nano-enabled scaffold device (NESD) incorporating dopamine nanoparticles into a polymeric scaffold for implantation into the brain parenchyma may be able to address and overcome the limitations of the current treatment for Parkinson's disease. Investigations performed cellulose acetate phthalate dopamine-loaded nanoparticles, employing an adopted emulsification-diffusion approach, produced particles with a notably high drug entrapment efficiency (63.05±0.354%) and desirable controlled drug release profiles (16.23% in 24hr). The employment of an experimental design, namely the Box-Behnken design, allowed for the attainment of optimized nanoparticles with high zeta potentials (.34.00mV), minimal particle size (197.20nm) and extended mean dissolution times (40.96). Barium chloride was employed to crosslink calcium-alginate scaffolds formulated in an adopted freeze-drying approach. Highly resilient (63.58±5.13) and porous structures (pore sizes of 100-400μm) were developed. A statistical approach employing the Box- Behnken design resulted in the formulation of a candidate barium-alginate scaffold displaying maximum matrix resilience (82.46%) and minimal matrix erosion (18.23%) over in 30 days. In addition, dopamine-loaded nanoparticles were dispersed within the scaffold that formed the NESD with the desired drug release profiles (5.12% in 168hr). Nanosystems of levodopa, nicotine and dopamine nanofibers were preliminary investigated. Drug release profiles for levodopa (4.21%: in 75hr), nicotine (0.42% in 24hrs) and drug entrapment efficiency for the polymeric nanofibers (75-85%) as well as data from scanning electron microscopy, zetasize analysis and drug release studies proved that these systems hold potential for the treatment of the disease and therefore require further investigation. Ex vivo cytotoxic studies carried out on the NESD and it's separate entities proved that the NESD was biocompatible with the white blood (70-80% cell viability in 24hr) and carcinomic brain cells (25% cell viability in 48hr) despite literature reports of dopamine being highly toxic in vivo. Extensive in vivo studies resulted in the development of a protocol for the surgical implantation of the NESD in the parenchyma of the frontal lobe of the rat brain. Scanning electron microscope images showed the gradual bioerosion (26% in 30 days) of the NESD while histological findings of the brain tissue proved clinically insignificant (absence of ischemia or chronic inflammation). Ultra Liquid Performance Chromatography revealed higher concentrations of dopamine in the CSF of rats which received brain implants of the NESD (28%) than in those administered the oral preparation, Sinemet (0.000012%) in 3 days.

A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy Johannesburg, 2016 / Oral drug delivery is acknowledged by many as the idyllic method of drug delivery due to its versatility and convenience of administration. Nevertheless, the bioavailability of drugs delivered via the oral route remains disputed. Classically, conventional marketed drug delivery systems release drugs in inconstant and unpredictable manners, leading to sub-therapeutic and in some cases toxic drug doses. Consequently, patient compliance is compromised, in turn having an effect on the success of the therapeutic intervention in question. One such limitation occurs in the treatment of Schizophrenia, with patients unable to comply with treatment due to multiple administration requirements. Sulpiride, an antipsychotic agent, displays notable efficiency in reducing both positive and negative symptoms of Schizophrenia. However, sulpiride has a low bioavailability and thus therapy requires the use of large doses, and hence multiple administrations. In addition, a large percentage of Schizophrenic patients present with concomitant mood disorders, namely ‘Schizoaffective’ disorder, which further necessitates the use of mood stabilizing agents. As a result, patients end up with a huge pill burden and are unable to comply with therapy and this leads to reduced clinical outcomes. A dual layered, xerogel-bioadhesive intestinal patch drug delivery system (ODLS) was thus designed, formulated, and evaluated for the site-specific delivery of two bioactives in the treatment of Schizophrenia with concomitant mood disorders in a time controlled-idiosyncratic manner. Ultimately easing compliance to complicated treatment regimens, enhancing bioavailability and improving patient compliance. The ODLS essentially comprises of a bi-layered tablet, layer one comprised of a sustained release semi-interpenetrating polymer network (s-IPN) xerogel and a layer two of embedded pulsatile release bioadhesive intestinal patches, with the system as a whole enteric coated for protection. Intestinal patches encompassed in layer two are fabricated of a backing layer, a drug loaded layer, a mucoadhesive layer, and a mucus cleaving layer. The ODLS employs a combination of sustained and pulsatile drug release mechanisms, in addition to intestinal retentive mechanisms. Furthermore, the system physically protects the drug delivery system from acidic or proteolytic degradation within the human gastro-intestinal tract. The present study utilized the use of bioadhesion for site-specific and gastro retentive drug delivery, with crosslinking being employed for rate-modulated drug delivery. Sulpiride and sodium valproate were selected as model drugs for the sustained release xerogel layer and the pulsatile bioadhesive patch layer respectively in this study as sulpiride is an antipsychotic with low bioavailability yet good antipsychotic activity and sodium valproate is the mainstay drug treatment for mood disorders in schizophrenia. Therefore, sulpiride would profit from the sustained release as it would improve bioavailability and hence patient compliance, whereas sodium valproate would benefit from the pulsatile release so as to avoid the well-known resistance to therapy due to prolonged exposure to drug. Thus these drugs would gain benefit from the site-specific controlled drug delivery offered by the ODLS. The primary aim of the sustained release s-IPN xerogel was to ensure delayed release of drug over 24 hours thus decreasing the need for multiple administrations and to maintain a steady state drug concentration. Film casting, a versatile technique was utilized in the fabrication of polymeric films to develop the bioadhesive intestinal patches. Preliminary in vitro investigations led to identification of a combination of polymers and crosslinking agent best suited to develop the system. A central composite design was employed for system optimization. The xerogel layer demonstrated that zero-order drug release was achieved after the crosslinking procedure. Delayed drug release fundamentally decreases the number of doses required daily and thus patient compliance and clinical efficacy is improved. The pulsatile release layer displayed distinct triphasic drug release after assembly of the intestinal patches, pulsatile release of drugs fundamentally reduced resistance to drug therapy as well as reducing pill burden. Furthermore, in vitro analysis of the ODLS showed that the xerogel layer behaved superiorly in terms of controlling drug delivery in a site-specific and prolonged fashion in comparison to a marketed gold standard. There exists no gold standard for pulsatile delivery of sodium valproate hence the pulsatile layer was tested against the marketed standard administered as a single dose. In vitro findings were substantiated by in vivo analysis in a white pig model. Results indicated that the systemic bioavailability of sulpiride was higher than the gold standard and drug release was prolonged in a zero-order fashion over 24 hours. Sodium valproate released in a triphasic manner over 24 hours thus reducing the risk of treatment resistance and decreased pill burden. To summarize, the ODLS was able to overcome the many challenges associated with oral drug delivery in schizoaffective disorder, by simplification of complicated treatment regimens, and hence improving bioavailability of drug delivery orally. The benefits associated with oral drug delivery have evidently been exploited by the present study, producing a versatile drug delivery system which can successfully deliver two bioactives simultaneously via individualistic release patterns, thus treating both conditions with a single oral dosage form with a single daily administration. / MT2016

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Public Health in the field of Hospital Management July, 2014 / BACKGROUND: The World Health Organization (WHO) has acknowledged the importance of maternal care and listed it as part of its Millennium Development Goals (MDGs). The 5th goal is focused on improving maternal health by reducing the maternal mortality rate by 75% by 2015. South Africa has aligned itself with the MDGs. The Gauteng Department of Health and Social Development has also embraced the MDGs and decided to improve its maternal health services. It has decided to target Intra-partum period for interventions to improve maternal health because intra-partum period is associated with a high rate of perinatal death from intra-partum hypoxia (4.8 per 1000 births) (National Department of Health, 2000), as well as a significant number of maternal death (8.7%) (NCCEMD, 2007). This study was planned to systematically study the clinical procedure performed during the intra-partum period at the Heidelberg Hospital (a semi - rural district hospital in the Lesedi Sub – district of Sedibeng District in Gauteng Province). AIM: To describe the clinical procedures and factors related to these procedures and maternal and neonatal health outcomes for the mothers admitted and delivered in the Maternity unit at Heidelberg hospital during one year period (1st April 2010 to 31st March 2011) METHODOLOGY: The setting of this study was the Maternity unit of the Heidelberg Hospital. A cross sectional study design was used based on retrospective review of routinely collected data for 12 months (2010 April 1st to 2011 March 31st). No intervention was done as a part of this study. The study variables included different clinical procedures (such as normal vaginal delivery, assisted vaginal delivery, caesarean section, evacuation of uterus, caesarean hysterectomy), socio-demographic profile of patients (such as age, gender, ethnicity, medical aid), clinical profile (such antenatal diseases, booking status, intra-partum complications, postpartum complications) and maternal and perinatal outcomes. RESULTS: The study found highest number of deliveries (78.6%) were normal vertex deliveries and a very few (1%) assisted and breech deliveries. The caesarean section rate was high (20.4%) as compared to the normal national target (12, 5%). Fetal distress and CPD was the main indications for caesarean section. The majority of women who delivered at Heidelberg Hospital maternity came from poor socio-economic class, mostly single, teenagers, and unemployed. They were the most vulnerable group in the Society. The majority of women were booked and referred from PHC clinic where they were booked for antenatal check-up. Pregnancy induced hypertension was the commonest obstetric problem encountered during antenatal period. Most women who delivered at Heidelberg hospital during the period were discharged without complications, no maternal deaths were reported. There were 8.1% preterm deliveries but a relatively high still birth rate which is of concern. CONCLUSION: The study was the first of its kind to be done at Heidelberg Hospital and the Sedibeng Health District. The study systematically analysed routinely collected data and identified high risk patients, who would require special attention. This study would hopefully assist the Hospital Management to realise the high rate of CS and to develop appropriate measures to reduce unnecessary C/S being done, and to strengthen referral systems. In addition, further study is necessary at clinic level in the sub-district to identify work-loads in the feeder clinics.

No description available.

Thesis (M.Pharm.)--University of the Witwatersrand, Faculty of Health Sciences, 2011.

These investigations are focused on the design and formulation of novel nonviral lipopolyamine vectors capable of efficiently and safely delivering DNA to the nucleus, and siRNA to the cytoplasm, in two tissue cultured (primary and cancer) cell lines. The thesis starts with a focussed literature review on the non-viral gene therapy (NVGT) vectors currently used in the formulation of DNA and siRNA. The first experimental part tests the ability of our novel lipospermines in NVGT, this includes structure-activity relationship (SAR) studies changing the: position, length, saturation or symmetry of the fatty chains of N4,N9-diacyl, N1,N12-diacyl and N4,N9-dialkyl spermines. The ability of these lipospermines in DNA condensation is investigated using ethidium bromide fluorescence-quenching, and gel electrophoresis (including gel shift and DNase protection) assays followed by nanoparticle characterization techniques (particle size and zeta potential). Transfection efficiency of pEGFP (using FACS) and cytotoxicity (using MTT) were studied in both cancer and primary cell lines and compared with Lipogen™ (N4,N9-dioleoyl spermine). Some of these novel lipospermines are shown to be as good as, but not better than N4,N9-dioleoyl spermine as efficient DNA transfecting agents. N4,N9-Dioleoyl spermine is the best transfecting agent from the all tested novel lipospermines displaying the lowest N/P ratio, highest transfection efficiency and the lowest cytotoxicity on both tested cell lines. We extended this SAR study to examine the same lipospermines in siRNA delivery. The ability of these compounds to bind siRNA was studied using the RiboGreen intercalation assay followed by similar nanoparticle characterization techniques. Transfection efficiency for delivery of Label IT® RNAi Delivery Control (using FACS) and cytotoxicity (MTT) were also studied in both cancer and primary cell lines, and compared with a market leader siRNA transfecting agent Trans-IT™. Twelve of these non-viral vectors, led by N4,N9-dieicosenoyl spermine and N4,N9-dierucoyl spermine, showed both transfection efficiency and cell viability over 75%.

Para ver la viabilidad del siguiente proyecto denominado PuppyTel, se realizó una investigación de mercado a través de diferentes canales de comunicación; y, en base a la información encontrada pudimos detectar que existe una demanda insatisfecha de personas que buscan encontrar una mayor variedad de productos y precios para el cuidado de sus mascotas. Por ello, realizamos el siguiente proyecto, el cual contiene un análisis del plan de marketing, operaciones, recursos humanos y financiero, que nos sirven para poner en marcha nuestra idea de negocio PuppyTel, la misma que, ofrecerá la mayor variedad de productos y precios para mascotas de manera online, dando la posibilidad de encontrar desde un juguete hasta pasta dental, pasando por placas de identificación o casas para las mascotas; los cuales, serán importados de USA, China, Francia, Alemania o fabricados en Perú; sin dejar de lado el abanico de precios para darle al cliente la facilidad de elegir desde algo muy económico hasta algo más premium. Finalmente, según la investigación realizada, el proyecto generará un retorno de 61% como mínimo para los inversionistas, con un periodo de recuperación de la inversión de 2.09 años y una rentabilidad del proyecto de 1.95 veces la inversión inicial. Por ello, creemos que PuppyTel es una idea de negocio rentable con un gran potencial de ventas y crecimiento constante. / To see the viability of the next project called PuppyTel, a market research was carried out through different communication channels; and, based on the information found, we were able to detect that there is an unmet demand from people seeking to find a greater variety of products and prices for the care of their pets. For this reason we carry out the following project, which contains an analysis of the marketing plan, operations, human resources and finance plan, which help us to implement our PuppyTel business idea, which will offer the widest variety of products and prices for pets online, giving the possibility to find from a toy to toothpaste, through identification plates or houses for pets, imported from the USA, China, France, Germany or manufactured in Peru; without leaving aside the range of prices to give the customer the ease of choosing from something very economical to something more premium. Finally, the project will generate a minimum return of 61% for investors, with a payback period of 2.09 years and a project return of 1.95 times the initial investment. Therefore, we believe that PuppyTel is a profitable business idea with great sales potential and constant growth. / Trabajo de investigación

No description available.

In this thesis nanoparticles consisting of a calcium phosphate core encapsulated by poly(lactic-co-glycolic) acid and polyethylenimine were developed for the delivery of siRNA in vivo. The nanoparticles were efficiently endocytosed by different cell types in vitro without exhibiting cytotoxic characteristics. Without possessing endogenous immune response activating properties, the nanoparticles had a highly preferable composition for the delivery of siRNA and subsequent gene knockdown. The delivery of siRNA with nanoparticles was tested in two different murine disease models: DSS-induced colitis as model for human IBD and a TH1-induced lung inflammation as model for COPD. In IBD and COPD chemokines and cytokines are predominant players in the progression of the inflammatory response. The local interference of cytokine signalling mediated by siRNA-loaded nanoparticles might therefore be a promising new therapeutic approach. In both murine models, the aim was to deliver siRNA directed against inflammation related cytokines by nanoparticles for the local treatment of mucosal inflammation. The local administration of nanoparticles loaded with siRNA to mice suffering from intestinal or lung inflammation led to significantly decreased target gene expression on mRNA as well as protein level in biopsies from the target tissues. Furthermore, reduced cytokine levels were accompanied by diminished inflammatory pathologies and augmented clinical signs of sickness. The results of this thesis indicate that a specific and local modulation of inflammatory responses by nanoparticle-based siRNA delivery is feasible and demonstrates a major therapeutic potential.