Bio-stimulation in Hypermobile Areas: The Role of Absorbable PLLA-PCL Threads in Modern Aesthetic Practice

The landscape of aesthetic medicine is shifting. Over the past number of years “Bio-stimulation” has become one of the most prominent buzz words in Aesthetic Medicine.

As some clinicians report that patients are becoming increasingly “filler shy” – along with the increase use of GLP-1 weight loss drugs – the demand for treatments that promote natural collagen production and subtle tissue support continues to rise.

As we age, it is suggested that we lose approximately 1-1.5% of our collagen per annum₁, leading to the development of fine lines and wrinkles. Repeated movement of the muscles of facial expression further compounds this process, with dynamic lines becoming increasingly etched into the skin over time and ultimately progressing into more problematic static lines.

Bio-stimulation offers clinicians tools to help patients stimulate collagen induction and to strengthen the skin where weaknesses are noted.

There are a number of clinical treatment options from medical micro-needling, device-based treatments and injectable gel products containing Poly-L-Lactic acid, Poly-Caprolactone or Calcium Hydroxy-appatite. The choice will very much depend on clinician preference, experience, presentation, patient budget and tolerance to downtime along with acceptance of various risk profiles of the products.

Hyper-mobile areas such as the peri-oral area, lower third and neck are some of the most affected areas with static lines and dimples caused by repeated contraction of muscles of facial expression. Importantly, the mobility in these areas makes injecting any gel-like injectable higher risk for the development of non-inflammatory nodules.

Before the introduction of Definisse™ Revitalise Threads, options in these areas were limited or risked the development of potentially difficult nodules which could not easily be reversed, leading to significant patient dissatisfaction and distress.

What are Definisse Revitalise™ Threads?

Definisse™ Revitalise Threads are absorbable monofilament barbed and smooth sutures of varying lengths, mounted on a needle and made from poly-L-lactic acid (PLLA) and ε-caprolactone (PCL). PCL provides rubbery properties, while PLLA ensures biocompatibility and biodegradability.₃ Also, PLLA enhances the synthesis of type 1 collagen in a concentration-dependent manner.₂

Due to their structure and composition these threads offer a very controlled bio-stimulation along their entire length. When inserted in areas of hyper-mobility they do not aggregate product to potentially result in non-inflammatory nodules.₃

How do the threads stimulate collagen?

Clinical studies have shown that once implanted, the threads stimulate a cutaneous reaction resulting in subcutaneous fibrosis and collagen production which remains stable for 12 months and beyond after resorption of the initial suture.₃

Studies have also confirmed that PLA can increase gene expression for collagen synthesis, mediated by increased expression of COL1A1 and COL1A2 genes responsible for Type 1 Collagen synthesis.₄ The same study showed an increase in elastin production.₄ In addition, it was demonstrated that there was an inhibitory effect on MMP-1 enzyme and increase in TIMP-1 and TIMP-2.₄ The study also found activation of the TGF-β/Smad signalling pathway resulting in greater proliferation and differentiation of fibroblasts.₄

What are the clinical indications?

Definisse™ Revitalise Threads can be used anywhere on the body. The main clinical indications include:

• Rejuvenation and preservation of youthful skin quality
• Crepey sun damaged skin
• Upper lip vertical lines, radial smile lines
• Crepey skin on neck

How technically challenging are these procedures?

Definisse™ Revitalise Threads are a relatively simple technique which can be employed by Doctors, Dentists and Nurses. They are placed intra-dermally or within the deep dermis.₃

The procedure can be an adjunct during toxin, dermal filler or tissue re-positioning with cog threads. They offer the patients a clinically effective, low down-time procedure to treat skin quality. Best results are seen in combination with Definisse™ Hydrobooster.

Combining with the Definisse® collagen modulator improves outcomes. A recent case series has demonstrated combining with the Definisse® Redensifying cream improved patient outcomes and satisfaction; this was also noted by investigators.₂

Definisse™ formulations incorporate SA1-III, a bioactive decapeptide derived from the C-terminal portion of Serpin A1, which inhibits protease-driven collagen degradation.₂ Additionally, the products contain a varying blend of high and low molecular weight hyaluronic acid, niacinamide, truffle extract and tocopherol.₂ Used synergistically as an eye contour cream, regenerating facial serum and redensifying moisturiser they can further enhance the outcome from Definisse™ Revitalise Threads.₂

Definisse™ Revitalise Threads now offer clinicians an additional and powerful tool in order to safely offer bio-stimulation in the more challenging hyper-mobile parts of the face where we might want to avoid injectable gel materials. Early clinical studies show promising and improved outcomes by combining these with Definisse™ KP1® skincare range.₂

These treatments offer patients a simple in-surgery and at-home blend of treatments which can be further augmented with the Definisse™ hydrobooster.

When clinicians are faced with difficult and challenging cases, we want to provide safe but effective solutions for patients which minimise downtime and risk of complications. Non-inflammatory nodules created by non-reversible filler may lead to poor outcomes clinically and challenging complications to deal with. Thereby having an additional tool which may minimise these risks is advantageous to both practitioner and patient.

References

1. Reilly DM, Lozano J. Skin collagen through the lifestages: importance for skin health and beauty. Plast Aesthet Res. 2021;8:2.
2. Santorelli A, Mentone A, D’Alessio FM, Uderzo S, Manni M, Wong V. The combined benefits of Definisse™ Revitalise Threads and Definisse KP1® Redensifying Cream treatments: a 19-patient case series. Life. 2026;16(3):465.
3. Wong V. The science of absorbable poly(L-lactide-co-ε-caprolactone) threads for soft tissue repositioning of the face: an evidence-based evaluation of their physical properties and clinical application. Clin Cosmet Investig Dermatol. 2021;14:45–54.
4. Zhu W, Dong C. Poly-L-lactic acid increases collagen gene expression and synthesis in cultured dermal fibroblast (Hs68) through the TGF-β/Smad pathway. J Cosmet Dermatol. 2023;22:1213–9.