Nanoencapsulation With Layer-by-layer Coating On Yeast Cells For Acid Resistant Functionalities

Yeast(Saccharomyces Cerevisiae)is one of the most important cells,which need food,warmth,and moisture to survive.In some cases,yeast is being introduced to different conditions where the cells are unable to survive,under these conditions,a protection layer on cells would help them thrive for a longer time.Especially the use of yeast in the food industry has proven to be a vital role for the yeast to show implemented functionalities by introducing coated cells in different products(e.g.,Yogurt).Thus,the exposure of the cell to the stomach acid under higher temperature could cause the release of coated functionality in a preemptive state.The lower p H is one of the most fundamental studies in this thesis,as acid resistance properties on PTFE would alone not be sufficient to coat the cells as PTFE treated on the yeast cell surface has shown toxicity with the cell.Firstly,we implemented Poly(ethylene glycol)(PEG),and Poly(isopropyl acrylamide)(PNIPAAm)to act as an enhancer towards the PTFE coating while allowing the cell to thrive longer under a corrosive environment.Further,as PTFE were homogeneous particles with neutral charges,the biggest challenge occurred in coating the cells as alone their PTFE coating would be unable to reach a high yield %.Allowing the PTFE coating to adhere to the cell surface,while allowing the cell to thrive under different environment,gives PTFE a great edge Adhesive layer Poly(Dopamine)(PDA)has proven to be a vital biopolymer to encapsulate the cell surface while maintaining the layer stability in PEG-PNIPAAm-PTFE coatings.I completed the cell synthesis to allow the cell to function in the changes of the environment while allowing the cell to be biocompatible towards the surrounding,especially under corrosive environment and analyzed the cell compatibility under higher and lower temperature.To understand the cell morphology and stability while under higher temperatures,we coated the cell to show the PEG-PNIPAAm-PTFE@PDA coated functionalities.Further,we analyze the PEG-PNIPAAm-PTFE@PDA coating and analyzes the structure stability while providing anti-corrosive functionality under mild temperatures while allowing the cell to release its delayed functionality under 37?.To identify the issues mentioned,we protected the cell with different layers of coating and understanding the impact of the cells in mild and higher temperatures.To solve this problem,using PTFE as anti-corrosive material,we surrounded the cell with PTFE particles,on PNIPAAm@PDA coated layer,to allow the cell to resist a corrosive environment,while measuring the viability and period.The coated layer stability proved to be successfully coated to work under tremendous stress from the corrosive environment.We also tested the cell and solved the viability thrive under higher temperature,as the cell under higher temperature turned hydrophobic,allowing the PNIPAAm@PDA to separate the PTFE coated layer in an induced environment.The cytoprotection LBL coating proved to be a great biopolymer coating as,allowing the cell to thrive by the implementation of PEG@PDA,and by resisting the penetration of PTFE nanoparticles by PNIPAAm also giving the protection of the cells from the toxicity of the outer coating,temperature,and corrosive environment.The successful coating of yeast cells showed us great potential for anti-corrosion under higher temperatures,while the data presented suggested the longer viability,solving the problem presented to the cell instability of the environment.