1. Bio-Polymer Modification and Advanced Therapeutics Laboratory, Centre for Nanostructures and Advanced Materials, Council for Scientific and Industrial Research, Pretoria, Gauteng 0001, South Africa
2. Emerging Research Area Platform, Next Generation Health Cluster, Council for Scientific and Industrial Research, Pretoria, Gauteng 0001, South Africa
3. College of Health Science, School of Laboratory Medicine and Medical Science, HIV Pathogenesis Programme, University of KwaZulu-Natal, Durban, KwaZulu-Natal 4041 South Africa
4. Faculty of Science, School of Chemistry, University of the Witwatersrand, Johannesburg 00000, South Africa