Microenvironmental modification and analysis of 3D cell culture using microgels

The complex, heterotypic, and dynamic microscale surroundings of cells, termed the cellular microenvironment, determines cell behavior. As such, efforts to characterize and modify cellular microenvironments are abound within bioengineering and related fields, with an increasing amount of research efforts being translated from 2D in vitro culture to 3D culture, due to the potential for increased in vivo relevance within 3D systems. Hydrogels are a particularly popular material for 3D cell culture based on their resemblance to native tissue. For example, PEG hydrogels are commonly used for their high modularity and bioinert nature, but they can exhibit some limitations due to nanoporosity. PEG microgels are able to retain the modularity of bulk PEG hydrogels while adding microporosity, injectability and heterogeneity to the system. By using PEG-acrylate microgels of 5.84 µm, we were able to create a miniaturized sandwich ELISA system that could detect gradients of 2.21- 21.86 ng/mL of IL-6 and 92.56 – 2259.08 ng/mL of MMP2 in 3D space. By using PEG-norbornene microgels of ~9.74 µm, varied stiffnesses of 5.72 and 24.44 kPa and tagged with fibronectin, collagen I, III or IV, we enabled the modulation of hepatic stellate cell activation. Further, by automating the distribution of these protein-tagged microgels, we created heterogeneous scaffolds to serve as high throughput ECM screening platforms for the quantification of hepatic stellate cell matrix remodeling and metabolic activity. The high throughput ECM screening platform could be expanded to other areas to identify ECM conditions that can lead to optimal directed differentiation, cell phenotype or drug efficacy. We believe these cellular microenvironment characterization and modification techniques can expand upon existing 3D cell culture platforms and allow for new insights into 3D cellular behavior.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Bioengineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2023

Author dc:creator

• Ryoo, Hyeon

Contributors dc:contributor

• Underhill, Gregory H
• Kong, Hyunjoon
• Perez-Pinera, Pablo
• Wang, Ning

• Microgels
• 3d Cell Culture
• Granular Hydrogels
• High Throughput Screening
• Sensor
• Il-6
• Ecm

Statement dc:rights

• Copyright 2023 Hyeon Ryoo

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/121301

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F121301