DEVELOPMENT OF REACTIVE POLYANIONS FOR ENCAPSULATION OF LIVE YEST CELLS WITHIN POLYMER HYDROGEL FILMS

Abstract

<p>Conformal coating is a promising method of encapsulating therapeutic cells for immunoprotection during implantation in the human body. Therapeutic cells can include donor-derived primary cells, genetically modified lab lines, or stem-cell derived cells, that can express an enzyme or hormone needed by the recipient. Layer-by-Layer (LbL) assembly, a common method for conformal coating, uses sequential deposition of alternating layers of positively and negatively charged polymers. This permits the preparation of small capsules with thin walls that maximize metabolic exchange while protecting cells from the hosts’ immune system. The current work describes the use of auto crosslinking synthetic polyelectrolytes to coat the surface of individual living yeast cells. It is proposed that such crosslinked coatings will provide greater protection than existing, non-crosslinked ones.</p> <p>The thesis also introduces new reactive polyanions formed by copolymerization of N-acryloxysuccinimide and acrylic acid (AA) using both free radical and photo induced radical polymerization. The resulting reactive polyanions bind under physiological conditions to poly-l-lysine coated calcium alginate hydrogel beads and spontaneously crosslink with the polyamine to form covalent networks of interest for long-term therapeutic cell encapsulation.</p>