School of Therapeutic Sciences (ETDs)
Permanent URI for this communityhttps://hdl.handle.net/10539/37954
Browse
4 results
Search Results
Item Design and development of a bioactive-loaded polymer-engineered neural device for potential application in reducing neurological deficits after spinal cord injuries and neuro-regeneration(University of the Witwatersrand, Johannesburg, 2017) Kumar, Pradeep; Choonara, Yahya Essop; Modi, Girish; Naidoo, Dinesh; Pillay, VinessTraumatic Spinal Cord Injuries (SCI), due to their devastating nature, present several interventional challenges (extensive inflammation, axonal tethering, scar formation, neuronal degeneration and functional loss) that need to be addressed before even a slight neuronal recovery can be achieved. Recent post-TSCI investigational approaches include support strategies capable of providing scaffold architecture to allow axonal growth and conformal repair. This research provided detailed insight towards the development and fabrication of six specialized Polymer-Engineered Neural Devices (PENDs): 1) poly(lactic-co-glycolic acid)-gliadin (PLGA-GLDN) nanofibrous mats, 2) polyacrylamidated chitosan (PAAm-g-HT) scaffold, 3) functionalized chitosan methoxypolyethylene glycol (CHT-mPEG) cryosponges, 4) polyacrylonitrile-elastin-collagen (PANi-EC) neurosponge, 5) methylcellulose-alginate-polyethylene glycol (MAP) thermogel, and 6) chitosan-luronic F127-β glycerophosphate (CHT-PF127-βGP) composite thermogel for potential restriction, repair, regeneration, restoration and reorganization post-SCI. The latest trends in biomaterials-based SCI intervention were reviewed, discussed and analyzed in detail throughout the thesis. The research also involved an in silico analytico mathematical interpretation of multi(biomed)material assemblies wherein quantification of energy surfaces and molecular attributes via atomistic, dynamic, and docking simulations was carried out. The in silico experimentation additionally confirmed the potential of curcumin as a bioactive of choice for SCI intervention. Curcumin and dexamethasone were incorporated into the compact scaffolds and the bioactive release was determined over a period extending up to 60 days. The PLGA-GLDN nanofibrous mats demonstrated the formation of a compatible blend among the component polymers at equal weight ratios (PG55) as confirmed by quantitative physicochemical characterizations. Image processing analysis (DiameterJ plug-in of ImageJ) was performed on the SEM images of nanofibers to quantify the size, porosity, and orientation of the samples. Nanofibers within the size range of 10nm and 250nm were obtained in case of compatible blend and the nano stack was used for in vivo implantation post-SCI. Polyacrylamidated chitosan (PAAm-g-CHT) was synthesized via a unique persulfate-mediated polymer slicing and complexation as determined by static lattice atomistic simulations. The graft copolymer so obtained was fabricated into an anisotropic neurodurable scaffold. The CHT/mPEG cryosponges showed unique morphological features such as fringe thread-like structures (CHT alone); hemispherical, pebble-like structures (CHT-mPEG); curved quartz crystal-like or crystal-flower-like structures (CHT-mPEG-CHO); and grouped, congealed, steep-sided canyon-like structures (CHT-mPEG COOH). A novel image processing protocol involving DiameterJ and ND plugins of ImageJ software was employed for analyses of the SEM micrographs in terms of % porosity, pore wall thickness and % xiiehaviorxii of the porous scaffolds. The PANi-EC interpenetrating polymer network neurosponges were synthesized employing free radical polymerization under acidic conditions wherein first-in-the-world spinomimetic scaffolds were obtained. The unique feature of the PANi-EC neurosponge was the formation of a fibrous neurotunnel architecture mimicking the native spinal cord. The physicochemical characterization revealed that the secondary structure of the peptide molecules (elastin and collagen) rearranged in the presence of PANi to their native extracellular matrix (ECM) form confirming the self-assembling nature of the polymer-peptide architecture. Furthermore, the PANi-EC neurosponge provided a perfect balance of matrix resilience and matrix hardness similar to the native collagen-elastin complex in vivo. Two very interesting tri-component thermogels were reported here viz. a simple blend thermogel comprising methylcellulose, sodium alginate and poly(ethylene glycol) and a complex thermogel incorporating chitosan, Pluronic F127 and β-glycerophosphate. Both the thermogels solidified at physiological temperature confirming their applicability in vivo. The outstanding feature of MAP thermogels was the formation of hydrogen bonded O-H…C=O which only formed in the tripolymeric blend while the bipolymeric blends showing no such interaction. We proposed that the MAP thermogel self-assembled into a repeating network structure represented by “PEG400-ALG-hydrophillicMChydrophobic}-{hydrophobicMC-hydrophilic}-ALG-PEG400” and the physical “compression” might have led to the formation of hydrogen bonded O-H…C=O among MC/alginate or PEG/alginate in the presence of PEG or MC, respectively. In case of the complex CHT/PF127/βGP thermogel, a unique triphasic gel-sol-gel transition xiiehavior was observed with the thermogel forming a gel-phase at lower temperatures (T<20°C), a sol-phase at intermediate temperatures (20°C35°C). The MTT proliferation studies indicated that all polymer engineered neural devices (PANi-alone matrix) were capable of efficiently supporting the growth of PC12 cells compared to the control over a period of 72 hours. The fundamental objective of this thesis was to test the applicability and capability of various biomaterial composites towards the repair and regeneration of neuronal tissue after traumatic spinal cord injury. Although drug-loaded scaffolds were also developed, only drug-free scaffolds (PLGA-Gliadin 5:5 electrospun nanofibers; PANi-Elastin-Collagen neurosponge; and Chitosan/Pluronic F127/β-glycerophosphate thermogel) were tested in vivo for the proof-of-concept. The 21-point scale BBB locomotor rating analysis demonstrated that PEND I (14), PEND II (19) and PEND III (18) provided significant motor recovery as compared to the lesion-control (5) group 28 days post-SCI and –implantation. The immunohistochemistry confirmed that reparative changes were accompanied by marked upregulation of iNOS, a notable influx of ED1-positive chronic inflammatory cells, the appearance of multinucleate cells characteristic of presumptive regenerative neuroblasts and near-complete loss of GFAP and NF-200 protein/structural integrity. Almost complete functional and neurostructural recovery was observed with post-SCI implantation of PEND II and III. In conclusion, the composite scaffolds tested in this research demonstrated immense potential in improving the neurological, neurochemical, and behavioral outcome after implantation post-SCI.Item The impact of lower limb amputation on quality of life: a study done in the Johannesburg Metropolitan area, South Africa(University of the Witwatersrand, Johannesburg, 2010-01-29T07:15:06Z) Godlwana, Lonwabo L.Background: The impact of non-traumatic lower limb amputation on participant’s quality of life (QOL) is unknown. In an effort to provide better care for people with lower limb amputation, there is a need to first know the impact of this body changing operation on people’s quality of life. Aim of the study: To determine the impact of lower limb amputation on QOL in people in the Johannesburg metropolitan area during their reintegration to their society/community of origin. Objectives: 1. To establish the pre-operative and post-operative: QOL of participants (including the feelings, experiences and impact of lower limb amputation during the time when they have returned home and to the community). The functional status of participants. Household economic and social status of these participants. 2. To establish factors influencing QOL. Methods: A longitudinal pre (amputation) test –post (amputation) test study utilized a combination of interviews to collect quantitative data and in-depth semi-structured interviews to gather qualitative data. Consecutive sampling was used to draw participants (n=73) for the interviews at the study sites pre-operatively. The three study sites were Chris Hani Baragwanath Hospital, Charlotte Maxeke Johannesburg General Hospital and Helen Joseph Hospital. Participants were then followed up three months later for post-operative interviews and key informants were selected for in-depth interviews (n=12). Inclusion criteria: Participants were included if they were scheduled for first time unilateral (or bilateral amputation done at the same time) lower limb amputation. The participants were between the ages of 36-71 years. Exclusion criteria: Participants who had an amputation as a result of traumatic or congenital birth defects were excluded from the study. Participants with comorbidities that interfered with function pre-operatively were not included. Procedures: Ethics: Ethical clearance was obtained from the Committee for Research on Human Subjects at the University of the Witwatersrand and permission was obtained from the above hospitals. Participants gave consent before taking part in the study. Instrumentation: A demographic questionnaire, the EQ-5D, the Modified Household Economic and Social Status Index (HESSI), the Barthel Index (BI) and semi-structured in-depth interviews were used. Data collection: Participants were approached before the operation for their preoperative interviews using the above questionnaires and then followed up postoperatively using the same questionnaires and some were selected to participate in semi-structured in-depth interviews three months later. Pilot study: The demographics questionnaire and the modified HESSI were piloted to ensure validity and reliability. iii Data analysis: Data were analyzed using the SPSS Version 17.0 and STATA 10.0. The significance of the study was set at p=0.05. All continuous data are presented as means, medians, standard deviations and confidence intervals (CI 95%). Categorical data are presented as frequencies. Pre and post operative differences were analyzed using Wilcoxon Signed-rank test. A median regression analysis (both the univariate and multivariate regression) was done to establish factors influencing QOL. Pre and post operative differences in the EQ-5D items and the BI items were analyzed using Chi square/Fischer’s exact depending on the data. Data were pooled for presentation as statistical figures in tables. Both an intension to treat analysis and per protocol analysis were used. A grounded theory approach was used to analyze the concepts, categories and themes that emerged in the qualitative data. Results: Twenty-four participants (33%) had died by the time of follow up. At three months, n=9 (12%) had been lost to follow up and 40(55%) was successfully followed up. The preoperative median VAS was 60 (n=40). The postoperative median VAS was 70. The EQ-5D items on mobility and usual activities were reported as having deteriorated significantly postoperatively (p=0.04, p=0.001respectively) while pain/discomfort had improved (p=0.003). There was no improvement in QOL median VAS from the preoperative status to three months postoperatively The preoperative median total BI score was (n=40). The postoperative median total BI score was 19. There was a reduction in function (median BI) from the preoperative status to three months postoperatively (p<0.001). The ability to transfer was improved three months postoperatively (p=0.04). Participants were also found to have a decreased ability to negotiate stairs (p<0.001). Mobility was significantly reduced three months postoperatively (p=0.04). During the postoperative stage (n=40), 38% of the participants were married. Most (53%) of the participants had no form of income. The highest percentage of participants in all instances (35%) had secondary education (grade10-11), while 25% had less than grade 5. Only one participant was homeless, 18% lived in shacks, 55% lived in homes that were not shared with other families. People with LLA in the Johannesburg metropolitan area who had no problem with mobility preoperatively (EQ-5D mobility item), who were independent with mobility (BI mobility item) preoperatively, who were independent with transfer preoperatively (BI transfer item) had a higher postoperative quality of life (postoperative median EQ-5D- VAS) compared to people who were dependent or had problems with these functions preoperatively. Being females was a predictor of higher reported quality of life compared to being male. Emerging themes from the qualitative data were psychological, social and religious themes. Suicidal thoughts, dependence, poor acceptance, public perception about body image, phantom limb related falls and hoping to get a prosthesis were reported. Some reported poor social involvement due to mobility problems, employment concerns, while families and friends were found to be supportive. Participants had faith in God. Conclusion: Participants’ QOL and function were generally scored high both preoperatively and postoperatively but there was a significant improvement in QOL and a significant reduction in function after three months although participants were generally still functionally independent. Good mobility preoperatively is a predictor of good QOL postoperatively compared to people with a poor preoperative mobility status. Generally, most participants had come to terms with the amputation and were managing well while some expressed that they were struggling with reintegration to their community of origin three months postoperatively with both functional and psychosocial challenges.Item The effect of a scissor skills program on bilateral fine motor skills in preschool children in South Africa including skill improvement, equivalence, transferability of skills and skill retention(University of the Witwatersrand, Johannesburg, 2010-01-27T12:43:24Z) Ratcliffe, IngridThe purpose of this study was to assess the improvement of scissor skills after a graded scissor skills program in preschool children in South Africa (SA). A bilateral fine motor skills assessment tool was developed for use in this research. This task-based assessment included every day activities required at school as well as personal management items. This research phase included the development of the test items and test instructions, scoring as well as validity and reliability testing of the assessment. A suitable scissor skills program was then developed for Grade 0 children in South Africa. The program was validated by a pilot study and also by a focus group of occupational therapists. Some changes were made to the picture selection, the grading of the program, as well as to teacher instructions on how to present the program before it was finalised and ready for use in the implementation phase of the research study. The implementation phase of the study included the individual assessment of 149 learners (mean age of 5 years 6 months), from three different schools in South Africa. The main aim was to establish the effectiveness of the scissor skills program by measuring skill improvement, transferability of skills and skill retention. A further aim was to compare the difference of skill levels of learners from various socio-economic backgrounds in South Africa. The results showed statistically significant improvement in scissor skills in all groups from the three different schools, as well as an ability to retain the learnt skills. Participants from lower socio-economic backgrounds demonstrated the least skill initially but made the greatest gains during the program, at times decreasing the gap between themselves and other participants. It was concluded that children benefited from a graded scissor skills program, which allowed them to improve and retain their scissor skills but improvement did not transfer to other fine motor tasks.Item Record review of patients with brain abscess and empyema.(University of the Witwatersrand, Johannesburg, 2010-01-22T10:28:25Z) Schwenke, Katherine LindaStudies of patients presenting with brain abscess (BA) and Empyema are not routinely focused on occupational therapy (OT). There is a paucity of literature on deficits other than hemiplegia. Aims of this study were to determine the relationship between BA, Empyema, motor and other deficits and whether an OT intervention protocol is needed. Record review was used to establish clinical presentation trends. Hemiplegia was the most common motor deficit and the majority scored below the norm on the Beery- Buktenika Developmental Test of Visual Motor Integration (VMI). Patients with Brain Abscess generally had more significant deficits than those with Empyema for both motor and process deficits. Part B followed up a small sample (n=8) which indicated clinical improvement on the VMI test with the score on the supplemental test of motor coordination remaining a concern. Occupational Therapy is recommended to address these issues based on the Occupational Therapy Practice Framework-II.