In Vitro Degradation of Polydioxanone (PDO) Lifting Threads in Microfocused Ultrasound

Objective: Analyze the static degradation time of polydioxanone (PDO) threads with or without the association of microfocused ultrasound, which are techniques for aesthetic purposes. Materials and Methods: In vitro assays were conducted in isotonic solution using smooth polydioxanone (PDO) threads divided into 2 groups (n=3): FPL (Smooth Polydioxanone Thread) and FPLU (Smooth Polydioxanone Thread with Ultrasound). The FPLU group underwent microfocused ultrasound. Both groups endured the following analyses: UV spectroscopy Absorbance and Scanning Electron Microscopy (SEM). Results: Absorbance by UV spectroscopy: The concentration levels of molecules in the aliquots showed that at 8 days both FPL and FPLU groups exhibited absorbance levels of 0.0040 (mol
⁻¹
/L.cm
⁻¹
) and 0.00585 (mol
⁻¹
/L.cm
⁻¹
), respectively. At 30 days, these levels were 0.0799 (mol
⁻¹
/L.cm
⁻¹
) and 0.0543 (mol
⁻¹
/L.cm
⁻¹
). At 60 days, the FPLU group showed significant increase to 0.2039 (mol
⁻¹
/L.cm
⁻¹
) compared to the FPL group at 0.1152 (mol
⁻¹
/L.cm
⁻¹
) reaching a degradation peaks at 60 days. At 90 days, the FPL group presented 0.1299 (mol
⁻¹
/L.cm
⁻¹
) and the FPLU group presented 0.2377 (mol
⁻¹
/L.cm
⁻¹
). SEM: Morphological differences were observed in both groups. Conclusion: FPLU group showed higher absorbance over time. Microfocused ultrasound accelerated degradation time PDO threads, diminishing its functionality.