A novel approach to oral therapy : preparation and in vitro analysis of microencapsulated engineered Lactococcus lactis cells secreting heterologous proteins

Lactococcus lactis are intensely being studied for the oral delivery of vaccines and other therapeutics to the mucosa of the gastrointesintal tract (GIT). In this thesis, we explore a new development by applying microencapsulation technology. A comparative study of the viability and protein secretion of free and alginate-poly-l-lysine-alginate (APA) encapsulated engineered L. lactis has demonstrated the effectiveness of this new system. The viability of microcapsules in in vitro culture conditions and simulated gastrointestinal (SGI) environments was also investigated. The latter condition exhibited inferior survival, and the attributing factors were identified. Subsequently, a novel system for the sustained delivery of a single-chain variable fragment (scFv) antibody targeting the human pathogen Helicobacter pylori has been developed using microencapsulated genetically engineered L. lactis cells. Studies herein demonstrate the sustained viability and protein secretion of the system showing the therapeutic potential to this approach. Additional studies are required, specifically, in vivo evaluation in experimental animals