Enhancing Injectability and Viability of Cells using Viscoplastic Lubricated Flows

Hydrogels have been used as scaffolds and structural supports for cell growth. However, injecting these hydrogels requires substantial forces which also lead to high shear in the cell and ultimately cell death. Current methods to mitigate this problem suffer from limited applicability, poor durability, lack of stability and no significant enhancement in injectability. Here, we propose a viscoplastic lubricated gel co-flow, where the flow of the cell-laden payload through needles is facilitated by coaxial lubrication from a lower yield stress gel, to mitigate shear death, enhance injectability and enable stable flow. In this study, we optimize fluidic and flow parameters to minimize drag and shear on the payload gel. We establish regime maps of stable coaxial lubrication using both simulations and experiments. The velocity profile inside the needle is plotted using PTV to visualize the shear-free transport of the inner payload. Experimentally, we were able to achieve a 4x reduction in injection force and 5x increase in plug region (zero-shear region). Finally, we propose a theoretical model to explain the simulations and experimental results.

Name thesis:degree_name

Master

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Mechanical Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2021

Author dc:creator

• Dhulipala, Somayajulu

Advisor dc:contributor.advisor

• Varanasi, Kripa K.

Statement dc:rights

• In Copyright - Educational Use Permitted
• Copyright MIT

Licence dc:rights.uri

• http://rightsstatements.org/page/InC-EDU/1.0/

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/138941

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/138941