Growth Factors: Physiology and What Research Reports

What growth factors are

Growth factors are naturally occurring proteins or polypeptides that carry instructions between cells. They are released by one cell, travel a short distance through tissue fluid or the bloodstream, and bind a matching receptor on the surface of a target cell. That binding switches on signalling cascades inside the cell that influence whether it divides, matures into a specialised cell type, migrates, produces matrix, or stays alive. A 2020 review of cytokines and growth factors described both classes as soluble protein mediators that act at very low concentrations through specific receptors to regulate proliferation, differentiation and survival in cultured cells and in tissues (PMID 31384960).

The boundary between "growth factor" and "cytokine" is historical rather than chemical. Most growth factors were named for the first activity someone observed — fibroblast growth factor for its effect on fibroblasts, nerve growth factor for its effect on neurons — even though later work usually showed each molecule acts on many cell types. This page is for educational purposes only and is not medical advice; consult a licensed physician about any health question or before making any medical decision.

Where growth factors come from in the body

There is no single growth-factor gland. Production is distributed: platelets release stored factors when they degranulate at a wound, macrophages and other immune cells secrete them during inflammation, fibroblasts and endothelial cells produce them in connective tissue and vessel walls, the liver is a major source of circulating insulin-like growth factor, and bone, cartilage, placenta and nervous tissue each make their own local repertoire. Many factors are also stored bound to the extracellular matrix, particularly to heparan sulfate chains, and are liberated when the matrix is remodelled. Chemistry work on sulfated oligosaccharides carrying an anomeric fluorinated tail examined exactly this kind of carbohydrate–protein interaction, and the researchers reported that the synthetic compounds bound growth factors in binding assays (PMID 37879181).

Major families and what the literature describes

What growth factors do in the body

Building and maintaining the skeleton

Skeletal tissue depends on tightly timed signalling. The 2019 developmental-biology review reported that FGF ligands and their receptors coordinate cartilage and bone formation, and that mutations affecting FGF receptor signalling underlie recognised human skeletal disorders (PMID 30902253).

Wound repair and tissue regeneration

Repair proceeds through overlapping inflammatory, proliferative and remodelling phases, and growth factors are described as the messengers linking them. A 2022 review reported that engineered growth factors have been studied and applied in trauma and burn management in China as part of a research and translation programme (PMID 35012265). A companion review on wound repair reported that growth-factor regulation of healing has progressed from laboratory characterisation toward clinical wound care, while raising unresolved questions about delivery and timing (PMID 35899329).

Blood vessel formation

New capillaries are needed for growth, healing and, unhelpfully, for tumours. Researchers reported detectable expression of angiogenic growth factors in canine squamous cell carcinoma tissue, consistent with the broader idea that tumours recruit vasculature through these signals (PMID 33006294).

Reproductive and developmental biology

A 2016 review in a clinical obstetrics and gynaecology journal examined growth factors and pathogenesis, describing how altered growth-factor signalling has been linked to disease processes in reproductive tissue (PMID 26527305).

How growth factors are measured and studied

Common approaches in the published literature include immunoassays of serum or plasma, immunohistochemical staining of tissue sections, gene-expression measurement, receptor-binding assays, and cell-culture experiments in which a factor is added to a defined medium. The bioprocess review noted that recombinant cytokines and growth factors are routinely supplied to cultured cells to direct their behaviour, which is why they are central to cell-therapy and biomanufacturing methods (PMID 31384960). Circulating-level studies extend into psychiatry: a 2017 review of alterations of growth factors in autism and attention-deficit/hyperactivity disorder reported that several growth factors have been measured at altered concentrations in these populations, while noting inconsistency across studies (PMID 28751869).

Why the term matters to peptide readers

Many compounds discussed in peptide literature are either growth factors themselves, fragments of them, or molecules said to influence their release or binding. Understanding the underlying physiology — that these are receptor-mediated signals with broad, context-dependent effects — explains why researchers treat them as double-edged. The IGF review reported that the same signalling that supports growth and tissue maintenance is also implicated in cancer biology and ageing, which is why growth-factor pathways are studied both as repair targets and as oncology targets (PMID 33080771). Consistent with that, a 2017 oncology review examined targeting of growth factors in hepatocellular carcinoma and reported that polysaccharide compounds have been investigated for their ability to interfere with growth-factor signalling in that disease (PMID 28454283).

Growth factors in applied settings: What Studies Report

Beyond the laboratory, growth factors appear in surgical and dental research. A 2025 review of growth factors and osseointegration in dental implants reported that growth factors have been studied as adjuncts intended to influence bone–implant integration (PMID 41393465). In neurology, the stroke review reported that growth factors were investigated in experimental models of ischaemic injury for effects on neuronal survival and repair, while emphasising translational obstacles such as delivery across the blood–brain barrier (PMID 17012059).

Limits of the current evidence

• Much of the mechanistic work is in cell culture or animal models, including veterinary tumour tissue (PMID 33006294).
• Circulating growth-factor measurements in neurodevelopmental conditions were reported as inconsistent between studies (PMID 28751869).
• Reviews of wound repair reported that delivery, stability and timing remain open questions rather than settled practice (PMID 35899329).

None of the material above describes a protocol, and none of the cited reviews should be read as endorsement of any particular use outside of the clinical and regulatory contexts they describe.

References

• Growth factors and pathogenesis (Best Practice & Research Clinical Obstetrics & Gynaecology, 2016)
• Cytokines and Growth Factors (Advances in Biochemical Engineering/Biotechnology, 2020)
• Insulin-Like Growth Factors in Development, Cancers and Aging (Cells, 2020)
• Alterations of Growth Factors in Autism and Attention-Deficit/Hyperactivity Disorder (Frontiers in Psychiatry, 2017)
• Expression of angiogenic growth factors in canine squamous cell cancers (Biotechnic & Histochemistry, 2021)
• Fibroblast growth factors in skeletal development (Current Topics in Developmental Biology, 2019)
• Growth factors and stroke (NeuroRx, 2006)
• Growth factors and osseointegration in dental implants - A review (Bioinformation, 2025)
• Progress and thoughts on the regulation of wound repair by growth factors (Chinese Journal of Burns and Wounds, 2022)
• Synthesis and interaction with growth factors of sulfated oligosaccharides containing an anomeric fluorinated tail (Bioorganic Chemistry, 2023)
• Targeting of growth factors in the treatment of hepatocellular carcinoma: The potentials of polysaccharides (Oncology Letters, 2017)
• Establishment of "Chinese way" for trauma and burn management based on the engineered growth factors research and application (Chinese Journal of Burns and Wounds, 2022)