Calcium sulfate microparticle size modification for improved alginate hydrogel fabrication and its application in 3D cell culture

Abstract

Calcium ion-crosslinked alginate hydrogels are widely used as a materials system for investigating cell behavior in 3D environments in vitro. Suspensions of calcium sulfate particles are often used as the source of Ca²⁺ to control the rate of gelation. However, the instability of calcium sulfate suspensions can increase chances of reduced homogeneity of the resulting gel and requires researcher’s proficiency. Here, we show that ball-milled calcium sulfate microparticles (MPs) with smaller sizes can create more stable crosslinker suspensions than unprocessed or simply autoclaved calcium sulfate particles. In particular, 15 µm ball-milled calcium sulfate MPs result in gels that are more homogeneous with a balanced gelation rate, which facilitates fabrication of gels with consistent mechanical properties and reliable performance for 3D cell culture. Overall, these MPs represent an improved method for alginate hydrogel fabrication that can increase experimental reliability and quality for 3D cell culture.

Graphical abstract

Keywords

calcium sulfate dehydrate / ball milling / particle suspension / alginate hydrogel / 3D culture / viscoelastic hydrogel

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