Materials Science

Gelation kinetics of thiol-methylsulfone (MS) hydrogel formulations for 3D cell culture

Authors

Abstract

Crosslinking chemistries that allow hydrogel formation within minutes are essential to achieve homogeneous networks and cell distributions in 3D cell culture. Thiol-methylsulfone (MS) crosslinking chemistry offers minutes-scale gelation under near-physiological conditions showing many desirable attributes for 3D cell encapsulation. Here we investigate the gelation kinetics and mechanical properties of PEG-based hydrogels formed by thiol-tetrazole methylsulfone (TzMS) crosslinking as a function of buffer, crosslinker structure, and degree of TzMS functionalization. Appropriate buffer selection ensured constant pH throughout crosslinking. The formulation containing cell adhesive ligand RGD and enzymatically-degradable peptide VPM gelled in ca. 4 min at pH 7.5, and stiffness could be increased from hundreds of Pascals to > 1 kPa by using excess VPM. The gelation times and stiffnesses for these hydrogels are highly suitable for 3D cell encapsulations, and pave the way for reliable 3D cell culture workflows in pipetting robots.

Content

Thumbnail image of Gelation kinetics thiol-MS gels_FINAL_ChemRxiv.pdf

Supplementary material

Thumbnail image of Gelation kinetics thiol-MS gels SI_ChemRxiv.pdf
Supporting Information
1H NMR spectra of pre-polymers and derivation of PEG molar masses, molecular characteristics of pre-polymers and peptides, calculation of pre-polymer concentrations for rheology, excess VPM experiment for R3, mass spectrometry analysis of disulfide formation in VPM solution.