Zwitterionic Microgel Scaffolds Support Matrix Accumulation by Regulating Protein Adsorption.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Surface Chemistry

Background:

• Substrate charge is critical for protein adsorption, cell adhesion, and biocompatibility.
• Zwitterionic polymers offer advantages like hydration, protein adsorption resistance, and biocompatibility.
• Microgel scaffolds enhance cell functions compared to bulk hydrogels.

Purpose of the Study:

• To investigate how substrate charge influences cell viability, spreading, and extracellular matrix (ECM) deposition in microgel scaffolds.
• To fabricate microgels with distinct substrate charges using emulsion-based microfluidics.
• To compare the performance of zwitterionic, nonionic, and negatively charged microgel scaffolds.

Main Methods:

• Fabrication of microgels with varying functional groups to control substrate charge using emulsion-based microfluidics.
• Characterization of protein adsorption onto charged substrates.
• Seeding human mesenchymal stromal cells (MSCs) onto microgel scaffolds and assessing cell viability, spreading, and ECM deposition.

Main Results:

• Charged proteins exhibited greater adsorption to oppositely charged substrates.
• Zwitterionic microgel scaffolds significantly promoted MSC viability and spreading compared to nonionic or negatively charged scaffolds.
• Zwitterionic scaffolds maintained ECM accumulation under inflammatory conditions, unlike nonionic or negatively charged scaffolds.

Conclusions:

• Substrate charge is a key factor influencing protein adsorption, MSC adhesion, and ECM deposition.
• Zwitterionic microgel scaffolds demonstrate superior performance for cell behavior and ECM maintenance in tissue engineering.
• These findings highlight the importance of substrate charge in designing advanced macroporous scaffolds.