Layer by layer encapsulation of PRM/DXS/neutravidin and antibody on calcium carbonate core

• Main Author: Liaw, Zi Yen.
• Other Authors: Bjoern Holger Neu
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Chemical engineering::Biochemical engineering
• Online Access: http://hdl.handle.net/10356/16775
• Institution: Nanyang Technological University

In recent years, there is an increasing trend of polyelectrolyte microcapsules researches that use CaCO3 particles as cores. CaCO3 is biocompatible and non-toxic, making it ideal for use in drug delivery systems. CaCO3 particles were prepared by mixing CaCl2 and Na2CO3 solutions. PRM and DXS polyelectrolytes were coated onto the CaCO3 cores using the layer by layer technique. Upon successful establishment of the PRM/DXS layers on the CaCO3 particles, the colloid systems were functionalized with biotinylated lipid, neutravidin and eventually, the biotinylated antibody. Fluorescein labelled polyelectrolytes, biotinylated lipids, neutravidin and antibody were used at each stage to check that the layer by layer absorptions were successful. The successful coating of biotinylated CD-14 antibody onto the neutravidin-biotinylated lipid-PRM (RITC)-[PRM/DXS]2 system was then used for cell interaction. The confocal results showed fluorescent in the core of the CaCO3. This shows that there was leakage of fluorescence labelled PRM into the CaCO3 cores. Bovine serum albumin (BSA) was added during the CaCO3 formation step to stabilize the core. During the layer by layer absorption of neutravidin, the exposed inner layers of PRM cause undesired attraction of neutravidin to PRM. BSA was also used in the reduction of exposed PRM. From the experimental results, the colloid sandwich system of CaCO3 to CD-14 antibody can be successfully formed using the layer by layer technique and making use of the biotin-neutravidin attraction. The interaction of the eventual system with cells produces desirable results that should be further studied. These results suggest that it is possible to form the colloid system of PRM/DXS/biotinylated lipid, neutravidin and antibody using the layer by layer technique. They also show the possibility of controlling the level of interaction the colloid systems have with the cells of interest. These results show great potential for improving the target specificity in drug delivery systems.