What kind of nutrients/growth factors are best for my cell culture?
Cell culture is an evolving practice that has a large impact on regenerative medicine. The process of cell culture relies on precise adjustments to culture conditions that impact culture outcome. Each cell type requires a specific set of signals for efficient growth. In addition, basic nutrients and media components are needed by all cell types. Hence, some media components are universal, while others are specific depending on cell type.
Universal Media Components to Maintain Cell Proliferation [1]
This is a list of universal media components to maintain cell proliferation.
- Energy: sourced from carbohydrates or sugars and is required to sustain cellular metabolism.
- Essential metals and minerals: such as calcium, magnesium, iron, and other trace metals are required to regulate metabolic pathways and cellular processes.
- Buffering agents: phosphates, acetates, and citrates maintain pH level, neutralizing acidification arising from metabolic activity.
- Nutrients: composed of proteins (or their building blocks: peptides and amino acids) or growth factors necessary to maintain cellular pathways and signaling. This component of media varies based on cell type and can be tailored to fit a specific need. Details about a few main cell types and their required nutrients are outlined below.
Media may also contain other ingredients such as indicators for pH change, selective antimicrobial agents, and gelling agents that facilitate cell culture practices. Although not directly affecting cellular proliferation, these media components impact cell culture performance.
Induced Pluripotent Stem Cells (iPSCs) and Fibroblast Growth Factor 2 (FGF2)
Pluripotent Stem Cells
Pluripotent stem cells are unique cells that can self-renew and can differentiate into nearly any other cell type including neurons, cardiovascular cells, liver cells, epithelial cells, and more.
iPSCs are a specific stem cell type that are created from reprogramming somatic cells into a pluripotent stem cell state. Growth factors influence iPSC behavior to proliferate or differentiate. FGF2 signals proliferation of iPSCs as undifferentiated cells.
FGF Growth Factor
FGF2 regulates the Mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathways [
2] that are critical for cell signaling cascades, including those that regulate cell proliferation and differentiation. FGF2 reduces spontaneous differentiation thereby maintaining iPSC cultures that can be expanded indefinitely. Because of this, FGF2 is a critical growth factor for maintaining iPSCs cultures.
Neuronal Cells, Brain Derived Neurotropic Factor (BDNF), and Glial Derived Neurotropic Factor (GDNF)
Neuron Stem Cells
Neurons are an important cell type that sends messages to control basic functions throughout your body. Neurons, normally found in brain tissue, can be generated from
stem cells. Pluripotent cells are first differentiated into neural progenitor cells (NPCs) that further differentiate into neurons. iPSC-derived NPCs can later be used to pattern 3D structures such as brain organoids. Growth factor signaling maintains neuronal growth and guides the types of neurons generated. BDNF and GDNF are two critical growth factors for neuronal differentiation and proliferation.
BDNF Growth Factor
BDNF activates several pathways including MAPK, phospholipase Cy, and phosphatidylinositol-3 kinase pathways which regulate transcription of proteins required for neuronal survival and differentiation. [
3]. BDNF promotes neuronal survival, axon elongation and branching, dendritic spine formation, and neuronal plasticity.
GDNF Growth Factor
GDNF activates pathways including MAPK, phosphoinositositide-3-kinase, ERK, and ATK pathways which encourage cell proliferation [
4]. GDNF promotes the survival of dopaminergic, motor, and cortical neurons, as well as enhances axon elongation and branching in dorsal root ganglion.
BDNF, GDNF, iPSCs and NPCs
BDNF and GDNF are used to differentiate iPSCs and NPCs into neurons and for maintaining high-quality progeny. These growth factors can also be used to maintain 3D neuronal organoids and significantly drive organoid patterning.
Retinal Pigment Epithelial (RPE) Cells, FGF2, and Epidermal Growth Factor (EGF)
RPE Stem Cells
RPE cells are a monolayer of cells found behind the photoreceptor layer in the eye. They carry out many functions that support photoreceptor cells in the overlying neuronal retina including the conversion and storage of retinoids, the absorption of scattered light, maintenance of the microenvironment and provision of nutrition [
5]. RPE cells grow in a monolayer and can remain quiescent for long periods once they’ve grown to fill their bounded area. This makes it possible for RPE cells to withstand high stress conditions.
FGF2 and EGF Growth Factors
FGF2 promotes RPE cell proliferation via the pathways described above for iPSC.
EGF activates several pathways including the ERK MAPK, AKT-PI3K, and PLC-γ1-PKC pathways which regulate proliferation and prevent unnecessary apoptosis [
6]. This allows EGF to ensure RPE cells survive during the quiescent phase.
FGF2 and EGF are critical growth factors for maintaining RPE cells and creating the least stressful environment for their growth. RPE cells grown under defined conditions are now being transplanted to treat macular degeneration.
Ways to Customize Nutrients to Meet Your Cell’s Needs
Many cell types require growth factors to direct their proliferation and differentiation. A variety of protocols describe the timing of when growth factors are added to culture specific cell types. Understanding growth factor requirements is necessary to ensure your cells are receiving the signals they need when they need it.
StemCultures currently offers FGF2, BDNF, GDNF, EGF, and Activin-A controlled-release growth factors to allow control of growth factor levels in your cultures. We are available to assist you to maintain high quality cell growth using FGF2, BDNF, GDNF, EGF, or Activin-A. StemCultures also offer custom controlled-release growth factor solutions that can be requested at
this link.
