Development of antibiotic loaded liposomal hydrocolloid dressings for application in wound healing
- Authors: Ntsalu, Vuyiseka
- Date: 2017
- Subjects: Wound healing -- South Africa Liposomes Hydrocolloid surgical dressings -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13957 , vital:27361
- Description: Wound healing, as a normal biological process in the human body, is achieved through four precise and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. However, many factors can interfere with one or more of these phases, thus causing improper or impaired wound healing. Maintaining a moist wound environment is crucial in facilitating the wound-healing process. The beneficial effects of a moist versus a dry wound environment include re-epithelization, tissue granulation, and repair. The use of hydrocolloid occlusive dressings in maintaining a moist wound environment has proven to be a useful adjunct in facilitating wound healing. Although hydrocolloid dressings have been widely used clinically in wound management, bacterial resistance, poor solubility and sustained drug release remain to be a problem for many of the drugs used in wound therapy. In chronic wound management, where patients normally undergo long treatments and frequent dressing changes, a system that delivers drugs into a wound site in a controlled fashion can improve patient compliance and therapeutic outcomes. Liposomes are small phospholipid vesicles that have been widely investigated as drug carriers for the delivery of therapeutic agents. They are spherical lipid vesicles consisting of phospholipid bilayers that improve the efficacy of the drugs by fusing with biological membranes, and eventually releasing their entrapped content into the cells or bacteria. The aim of this study therefore, is to develop a new bacitracin-based controlled release hydrocolloid dressing, with good absorptive properties for improving the efficacy of antibiotics in wound healing. HPLC (high-pressure liquid chromatography) assay of bacitracin was performed for quantification of the drug. Liposomes were prepared using thin film hydration and extrusion methods. Liposomes were also characterized based on their ideal particle size and encapsulation efficiency, and then incorporated into the different ratios of chitosan/gelatin hydrocolloid films. The films were prepared with increase in gelatin concentration and were evaluated for folding endurance, tensile strength, water absorption capacity, morphology, drug release kinetics, antimicrobial activity and stability. The morphology of these films was found to be very smooth and homogeneous proving a good compatibility between the two polymers. With increase in gelatin concentration, folding endurance, water absorption capacity, tensile strength, drug release kinetics and antimicrobial activity were increased. The antibacterial activity against various bacterial species was improved in the bacitracin loaded hydrocolloid films as compared to the blank films. Based on the findings above, it can be concluded that chitosan/gelatin films at 1:3 proportion is a successful wound dressing for wound management with improved wound healing properties than other formulations. This formulation is a potential candidate for the development of alternative pharmaceutical dosage forms, for the treatment of bacterial infected wounds, based on the activity of the eco-friendly chitosan matrix added to the bacitracin activity. In this work, chitosan also demonstrated a great potential as a dressing for advanced wound therapy and confirmed its good biocompatibility and potential to provide, in combination with liposomes, sustained drug release which is highly beneficial for wound treatment. The addition of gelatin improved the water affinity of the films and facilitated water mediated cross-linking process.
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- Date Issued: 2017
Optimising syzygium cordatum dye extraction and subsequent cotton dyeing incorporating organic electrolytes
- Authors: Gamedze, Nombuso Faith
- Date: 2017
- Subjects: Dyes and dyeing -- Cotton Syzygium cordatum
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/19509 , vital:28888
- Description: The present investigation was carried out to optimize the extraction of natural dye from Syzygium cordatum,bark trees and then to evaluate its use in the dyeing of cotton fabric incorporating organic electrolyte. The bark was collected from recently fallen trees and twigs pruned from old trees, since they have greater dye content than the younger trees, dried for two weeks, crushed with a hammer and ground into powder. Grinding of bark was done to ensure a uniform particle size with a large surface area to facilitate quick extraction. The relevant conditions for natural dye extraction using a methanol/water mixture were optimized by Response Surface Methodology (RSM), with the help of Design Expert Version 7.0. The central composite design (CCD) was applied to design experiments for the evaluation of the interactive effects of the three most important operating extracting variables namely, temperature, time and liquor volume on 25g bark powder. This approach decreased the required number of experiments, and the following optimized extraction conditions were derived; temperature 700C, time 51minutes and material-to-liquor ratio 1:16. Dye used for subsequent dyeing was extracted using the optimized conditions. To determine the best conditions for dyeing cotton fabric with the dye extract, dyeing was carried out in a rotating canister machine, using two different organic electrolytes, namely trisodium nitrilo triacetate (trisodium NTA) and dimethylformamide, as mordants. The use of organic electrolytes, as mordants, was to ensure eco-friendliness of the dyeing, and with a maximum concentration of 3g/L being used to reduce the effluent load. Three different mordanting techniques, namely simultaneous, pre-mordanting and post-mordanting were investigated so as to establish which is best. The impact of the two organic electrolyte mordants on certain physical properties of the cotton fabric was also determined. The dyeing of cotton with theSyzygium cordatum bark dye extract, in conjuction with an organic electrolyte, generally showed good results, with trisodium NTA superior to dimethylformamide as a mordant. An increase in trisodium NTA mordant concentration increased dye exhaustion and a dye exhaustion of 23.7% being achieved with 3g/L pre-mordanting. This is still relatively low, however, and the use of an exhausting agent needs to be explored. The fabric dyed with a mordant, exhibited good wash, rub and perspiration fastness, with trisodium NTA superior to dimethylformamide. The use of trisodium NTA increased the strength of the dyed fabric whereas the use of dimethylformamide decreased it. In general, pre- and simultaneous mordants were better than post-mordanting. It has been shown that the dyeing of cotton, using Syzygium cordatum bark dye extract, in conjuction with an organic electrolyte, particulary trisodium NTA, has potential and can be recommended for craft applications. Optimised conditions for dye extraction and cotton dyeing have been derived and which can be recommended for use by crafters in Swaziland.
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- Date Issued: 2017
Views of HIV and AIDS amongst rural secondary school youth: an exploratory study
- Authors: Daniels, Brendon Mara Laurence
- Date: 2015
- Subjects: Sexually transmitted diseases -- Study and teaching Communicable diseases -- Prevention High school students
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/11460 , vital:26928
- Description: The HIV and AIDS epidemic continues to affect communities worldwide particularly so in South Africa. Youth, also the so-called Coloured youth, continue to remain at risk of infection, in spite of having been exposed to information about HIV and AIDS. This study explores the views of Coloured secondary school youth in a rural town in the Eastern Cape, on HIV and AIDS. Fifteen secondary school learners, both boys and girls, from Grades 10 to 12 were purposively selected. This qualitative study, framed within an interpretivist paradigm, draws on a phenomenological methodology. The data was generated from using drawing and focus group interviews and analysed using thematic analysis. The research adhered to ethical principles and trustworthiness was ensured. Constructivism and Bronfenbrenner’s bio-ecological systems theory were used to frame the study and to make meaning of the findings. In response to the primary research question, What views do Coloured youth attending a secondary school in a rural town have of HIV and AIDS?, five themes emerged, namely: individuals spread HIV, impoverished family life increases youth vulnerability to HIV, youth under pressure from peers knowingly engage in risky behaviour, misconceptions fuel the epidemic, and HIV and AIDS “captures the community in its net”. Drawing on the findings and in response to the secondary research question, What guidelines can be developed to assist educators to facilitate learners taking action against the spread of HIV and AIDS?, several guidelines were developed. They suggest that teachers should use participatory pedagogies to engage secondary school learners when teaching HIV and AIDS, build self-esteem in their learners, assist learners in dealing with peer pressure, engage learners in erasing misconceptions, and enable learners to break free from being “caught in the net” of HIV and AIDS. Collectively these guidelines could enable learners to take action in protecting themselves and their community against the spread of the HI virus. The study concludes that the views that Coloured secondary school learners from a rural town have about HIV and AIDS show their awareness of the realities of the epidemic affecting the individual, the family, the school and their community. They have constructed their views of HIV and AIDS in a way which shows their understanding of the complexities of the epidemic.
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- Date Issued: 2015
An economic analysis of the 2007 SCB conference
- Authors: Wait, Requier
- Date: 2010
- Subjects: Biodiversity conservation -- Economic aspects -- South Africa , Conservation biology -- South Africa , Biology -- Societies, etc , Managerial economics -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8981 , http://hdl.handle.net/10948/1131 , Biodiversity conservation -- Economic aspects -- South Africa , Conservation biology -- South Africa , Biology -- Societies, etc , Managerial economics -- South Africa
- Description: The Society for Conservation Biology held their 21st annual conference in Port Elizabeth during July 2007. This was the first SCB conference hosted on the African continent. Over 1500 conservation professionals and students from throughout the world were brought together by the SCB annual meeting. The local organizing committee was interested in the economic impacts associated with the conference and approached the NMMU Economics Department to conduct an economic impact assessment of the conference. The Economics Department invited the researcher to undertake this study towards obtaining an MCom degree in Economics. The economic impact of conferences stems from two sources, namely: expenditure by delegates (the demand-side) and the expenditure by conference organizers (the supply-side). The study focused on the economic impacts of the conference for the Eastern Cape. The conference expenditure produced an increase in demand in the Eastern Cape. Only new expenditure originating from outside the Eastern Cape were considered. An increase in the demand for one industry’s output will create additional demand for the outputs of its supplying industries, because industries are connected through forward and backward linkages. These inter-industry linkages produce a multiplier effect. The initial direct conference expenditure created secondary impacts. The latter were indirect and induced expenditures. In addition to secondary impacts, the SCB conference produced spill-over impacts. The spill-over impacts of the conference were noted (but not quantified). The expenditure by delegates was determined by means of a delegate expenditure questionnaire conducted during the conference. The expenditure by the conference organizers was determined in consultation with the organizers, using their financial statements. The multiplier impacts were estimated by means of an input-output (IO) analysis, using a Social Accounting Matrix (SAM) of the Eastern Cape as the underlying database. These multipliers (Type 1 and 2 multipliers) were estimated using open and closed multiplier models. It was deduced that the 2007 SCB conference created a significant and positive net economic impact in the Eastern Cape. The total direct cash injection of the conference was R12.141 million. Using a Type 1 multiplier this direct stimulus is estimated to have caused an extra R16.502 million increase in gross output. Using a Type 2 multiplier this direct stimulus was estimated to have caused a R19.884 million increase in gross output. The total cash injection of the conference contributed R6.093 million to GVA in terms of a Type 1 multiplier and a R7.344 million increase in GVA in terms of a Type 2 multiplier. Household incomes in the Eastern Cape were increased by R3.384 million. These results confirm that the hosting of major events and conferences is indeed a tool for promoting regional economic development.
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- Date Issued: 2010