Title: Cyclodextrin Biomaterials for Delivery of Active Ingredients

Biography:

Baghali G. Mathapa is currently a senior chemistry lecturer at Botswana University of Agriculture and Natural resources. He holds BSc Chemistry and MSc Physical Chemistry degrees from the University of Botswana and a PhD in chemistry from The University of Hull, UK. His PhD studies was focused on colloid and interface science with particular emphasis on cyclodextrin materials for microencapsulation of active components. His work involved synthesis and characterization of cyclodextrin based core-shell microcapsules, solid-core microcapsules, cyclodextrin based colloidosomes, surfactant free emulsions and cyclodextrin cyborg cells.

Abstract

Cyclodextrins are “bucket-shaped” molecules derived from starch with ability to form host-guest inclusion complexes with hydrophobic molecules of the right sizes. For this reasons, cyclodextrins find applications in a wide range of every day formulations as nano-carriers of active ingredients. On the other hand, yeast cells have also been explored as micro-encapsulating materials. Combining cyclodextrin and yeast cells has potential to reduce the toxicity in microencapsulation technology hence improving the well-being of consumers. These two materials are food grade and combing them will have a synergic effects which will improve their performance. Two alternative approaches for surface functionalization of Saccharomyces cerevisiae cells with cyclodextrin molecules without affecting the cell viability are presented. In the first strategy, cyclodextrin molecules were covalently attached to the glycoproteins on the cell wall using epichlorohydrin as a cross-linking agent. The second strategy of interfacing of the cells with CD involved alternating layer by layer deposition of cyclodextrin sulphate and polyallylamine (PAH) on the cell surface. The formation of host–guest inclusion complexes of a dye with the grafted cyclodextrins was used to estimate the average number of CD molecules grafted per cell. The information generated indicated that more than one monolayer of CDs on the cell surface within the surface layer surrounding the yeast cell membrane. Fluorescein diacetate was used to check the viability of the cells after functionalisation. Living cells functionalised with CDs may find many potential applications as they can be loaded with drugs, immunosuppressants and other molecules forming inclusion complexes with their cyclodextrin interface. Therefore, such cells can be used as selective biosorbents in polluted waters, drug delivery, cell therapy and cell implant applications.