Abstract

Cell Encapsulation into Alginate Hydrogels Using Microfluidics and Viability Studies

Venkat Gundabala, Associate Professor, Indian Institute of Technology Bombay

Bacterial cells encapsulated into biomaterials such as hydrogels have numerous applications as water disinfectants, probiotics, and food conservatives. In recent years, droplet based microfluidics has emerged as a facile route to 3D microencapsulation. Application of electric fields during droplet generation can provide additional control over the droplet size. In this work we develop a complete on-chip method to couple electric fields with chemical gelation, that requires low electric field strengths to achieve size reduction. For this we employ a cost-effective 3D glass-PDMS (Polydimethylsiloxane) microfluidic device that facilitates droplet generation, manipulation, and solidification; all using a single device. In this work, we demonstrate encapsulation of E. coli. into alginate beads in the presence of electric fields and perform a comprehensive spatio-temporal cell growth and viability studies. E. Coli. encapsulated alginate beads are generated by coalescence of cell laden sodium alginate droplets with calcium chloride plugs to induce chemical gelation. We perform comprehensive confocal imaging in the spatial and temporal domains and demonstrate high viability (~ 90%) and uniform growth of the encapsulated cells. In summary, in this work we show on-chip manipulation of droplet size coupled with chemical gelation as a useful cell encapsulation technology.