Biophysical Influence of Nanofiber Networks to Direct Pericyte Aggregation into Spheroids

Multicellular spheroids have emerged as a promising tool for drug delivery, cancer therapy, and tissue engineering. Compared to 2D monolayers, spheroids provide a more realistic representation of the 3D cellular environment, enabling better understanding of the signaling cascades and growth factors involved in vivo. The formation of in vitro spheroids involves the aggregation of several cells that proliferate to grow into larger spheroids. Biophysical cues provide crucial information for the cells to assemble into 3D structures. We used suspended fiber networks to demonstrate a new way to form and spatially pattern spheroids comprised of human pericytes. We show that fiber architecture (aligned vs. crosshatched), diameter (200, 500, and 800 nm), and contractility influence spheroids in their spontaneous formation, growth, and maintenance, and report a dynamic trade of cells between adjacent spheroids through remodeled fiber networks. We found that aligned fiber networks promoted spheroid formation independent of fiber diameter, while large-diameter crosshatched networks abrogated spheroid formation, promoting growth of 2D monolayers. Thus, a mixture of diameters and architectures allowed for spatial patterning of spheroids and monolayers within a single system. We further quantified various dynamic interactions and describe the forces involved during spheroid formation, cell efflux from spheroids, and show the loss and recovery of spheroid forces with pharmacological perturbation of Rho-associated protein kinase (ROCK). Thus, we develop new insights on the dynamics of spheroids using suspended fiber networks of varying diameters and architectures, with the potential to connect matrix biology with developmental, disease, and regenerative biology.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2023

Author dc:creator

• Sharma, Sharan

Chair dc:contributor.committeechair

• Nain, Amrinder

Committee members dc:contributor.committeemember

• Phillippi, Julie A.
• Paul, Mark R.

• Spheroids
• pericytes
• nanofibers
• spheroid forces
• contractility

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:37722

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/115851