Definition
Polynucleotides are polymers made of nucleotide chains. They constitute the building blocks of DNA and RNA. In aesthetic and regenerative medicine, they are classified as biostimulators. They have recently become a very trendy treatment, despite having been used in Korea since the mid-2000s.
Origin
Most polynucleotides used in medical aesthetics are extracted from the DNA of salmon or trout milt (sperm cells). Salmon was chosen because of its biocompatibility with human skin and DNA. This means fewer allergic reactions or immune-system responses.
The use of sperm cells is due to their purity and concentration, as well as the ease of extraction and isolation.
Is it really sperm cells that are injected
The answer is no. The sperm cells are initially highly purified, which means that all proteins and lipids are removed. All the “fish products” are stripped out and eliminated, which means that the final product cannot cause allergies in people with fish allergies. Finally, the fragmented DNA chains are suspended in a sterile, water-based gel, ready to be injected.
What are they used for
Collagen increase
As mentioned, polynucleotides are considered biostimulators. This means that they act as messengers that stimulate fibroblasts to produce more collagen. This increases skin elasticity.
Hydration
Polynucleotides have also been shown to increase skin hydration by attracting water.
Tissue healing
They have been shown to reduce inflammation and help with tissue repair. They are often used in conditions such as rosacea.
Applications
- Dark circles and skin laxity under the eyes
- Fine lines and mild sagging
- Scar tissue
- Inflammatory skin conditions such as rosacea
Polynucleotides vs hyaluronic acid
Hyaluronic acid is used for volume replacement and hydration. It causes physical stretching of the skin and helps to diminish overall sagging, depending on how it is injected and which type of acid is used. It is, however, not a strong collagen stimulator.
Polynucleotides, on the other hand, are considered biostimulators and thus have a direct effect on collagen stimulation and increase. Other biostimulators known in aesthetics are Radiesse (calcium hydroxyapatite) and Sculptra (PLLA).
What to expect after the injection of polynucleotides
- Polynucleotides are injected in small papules in the upper dermis. These papules may be visible for up to 48 hours after treatment.
- Some swelling and redness can be normal in the first 24 hours after injection.
- Bruises are also a common complication.
- Itching and slight tenderness are also possible.
Side effects and complications
Common side effects include lumps and nodules.
Less common side effects include allergic reactions or infection due to poor hygiene during injection.
A very rare complication is vascular occlusion due to an injection performed too deep into a blood vessel.
What do the studies say about polynucleotides
There are currently over 100 publications online on the subject, spanning the past 50 years, with a recent boom in the past 10 to 15 years. Most of them are primary clinical studies published in PubMed.
The general message is that polynucleotide injections offer significant improvements in skin texture, elasticity and wrinkle reduction through tissue regeneration. Moreover, these studies report a highly favourable safety profile with minimal risk of severe complications, although they frequently highlight the need for larger sample sizes and standardized treatment protocols.
