Traditional cell culture is based on two-dimensional growth that creates flat monolayers. Although this method has been a foundation for in vitro studies, researchers are finding that scaffolding with a support matrix from various types of hydrogels yields better results, with cells showing more natural behavior.
This guide to synthetic hydrogels will answer questions on how to successfully grow cells in three dimensions and explain the difference between synthetic and biological 3D cell culture hydrogels.
What Are Hydrogels?
According to Elizabeth Abraham, Market Manager, 3D Cell Culture portfolio at Corning Life Sciences, hydrogels are biomaterials that absorb significant volumes of water and are, therefore, hydrophilic in nature. When used in cell culture, they self-assemble into a 3D structure that supports cell growth. With hydrogels, instead of cells growing on a surface as a monolayer, they aggregate and grow into 3D structures that can mimic tissue and organ anatomy.
Products for 3D cell culture hydrogels can be natural or synthetic. Examples of natural hydrogels include Corning® Matrigel® matrix, a natural extracellular matrix (ECM) product containing collagen and laminin harvested from Engelbreth-Holm-Swarm (EHS) mouse sarcoma cells. The ECM derivatives specifically encourage cell growth and assembly since they contain relevant surface signaling structures that interact with cell-surface receptors to influence behavior.
As a solubilized basement membrane preparation, Matrigel matrix encourages attachment and differentiation for a variety of adherent cells, including epithelial and tumor cell lines.
What Are Synthetic Hydrogels?
Biological products are naturally derived from cell lines to promote cell adhesion and growth. Synthetic versions are similar but are created and engineered de novo as single constituents or customized blends. Abraham describes them as "networks of covalently or ionically cross-linked homopolymers or co-polymers and polymerization of synthetic monomers that result in the hydrogel structure." They mimic natural hydrogels, but give researchers more control and flexibility since the components in the hydrogel are defined.
Alejandro Montoya, Senior Product Manager for Advanced Cell Culture at Corning Life Sciences explains, "The physiochemical properties used in the formulations of synthetic hydrogels will help determine their functional possibilities."
Abraham further expands on this customization potential: "Synthetic hydrogels can also be classified based on how they get cross-linked: physical, chemical, and enzymatic. In addition, the cross-linking can be time, temperature, pH, photopatterning, or interpenetrating polymer network dependent. The composition and the cross-linking used can impact many properties of these synthetic hydrogels, such as stiffness, elasticity, porosity, degradation, cell adhesion, and bioactivity."