Abstract:
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This project’s goal is the production of biopolymeric microparticles of different sizes and chemical specifications and to use them as microcarriers in dynamic cell cultures. The cell culture conditions are to be optimized to allow the highest seeding and proliferation rate possible for cells.
This work is divided into two main parts. First, polylactic acid microparticles of two different sizes are fabricated by using a green method, and functionalized with proteins carrying adhesive motives. This functionalization aims at giving the particles the ability to carry and deliver cells to a specific tissue. Secondly, those microparticles are used as microcarriers in a dynamic cell culture. The impact of different parameters on the cells’ seeding and proliferation, such as the size of the microparticles, the grafted protein, the type of impeller, the stirring rate, or the impeller geometry, are studied.
Microparticles of appropriate sizes have been successfully produced. The functionalization process has led to an effective attachment of collagen and elastin-like recombinamer (ELR) molecules.
Large microparticles functionalized with collagen yielded higher seeding rates than all other types of microparticles. Nevertheless, cells do not proliferate for all samples with the spinner flask design we used.
The impact of the mechanical stirring has also been assessed. Indeed, a lower stirring rate triggers a slightly higher seeding efficiency. Furthermore, the use of an anchor-shaped impeller yields slightly higher seeding efficiencies than a paddle-shaped impeller.
Stirring during the seeding phase has as well an important impact on cells seeding. No stirring during the first 24 hours of the cell culture proved to yield higher seeding efficiencies than alternate stirring during 2 hours.
Proliferation was not achieved during this project. Nevertheless, various seeding efficiencies were obtained, depending mainly on the microparticles’ physical and chemical features, and the mechanical stirring conditions. |