# Hydrolysis of polydioxanone sutures in contact with hyaluronic acid of different concentrations: an in vitro study

## TL;DR

This study examines how different concentrations of hyaluronic acid affect the breakdown of PDO threads used in facial treatments.

## Contribution

The study provides new empirical insights into how HA concentration influences the hydrolysis of PDO threads in vitro.

## Key findings

- PDO threads in 5 mg/mL HA showed the least degradation over time.
- PDO threads in 25 mg/mL HA degraded significantly more, with higher absorbance and structural changes.

## Abstract

Facial tissue repositioning with polydioxanone (PDO) thread is an effective alternative for stimulating collagen, treating sagging skin, and defining facial contours. When combined with hyaluronic acid (HA), further research is needed, as it has not been widely explored in the literature. This in vitro study investigated the hydrolysis pattern of spiculated PDO threads (I-Thread, 19G x 10 mm, USP-0) in contact with six different concentrations of HA (5, 12, 15, 17.5, 20, and 25 mg/mL). Ten cannulated PDO spiculated threads were fragmented into three and submerged in 1.0 mL of HA in test tubes at 37 °C, forming six groups: G1 (5 mg/mL NCTF 135 HA), G2 (12 mg/mL Volite), G3 (15 mg/mL Volbella), G4 (17.5 mg/mL Volift), G5 (20 mg/mL Voluma), and G6 (25 mg/mL Vollux). Optical and scanning electron microscopy and spectrophotometric degradation were performed at baseline, 1, 15, and 30 days. Statistical tests were applied at the 5% significance level. The results showed that the hydrolysis pattern of the threads varied with HA concentration. G1 (5 mg/mL NCTF 135 HA) maintained stability with lower absorbance values throughout the evaluation period (p < 0.013), suggesting less degradation. However, G6 (25 mg/mL Vollux) showed significantly higher absorbance and more pronounced structural changes (p < 0.001), indicating greater degradation. These findings suggest that HA concentration may influence the hydrolysis of PDO threads.