THE COMPARATIVE STUDY OF THE EFFECT OF LOW-INTENSITY BROADBAND AND LOW-INTENSITY PULSED ULTRASOUND ON THE AMPUTATIONAL MODEL OF WOUND

<jats:title>Abstract</jats:title> <jats:sec> <jats:title>Background and aim</jats:title> <jats:p>Trauma healing with low-intensity ultrasound is effective for different types of injuries affecting both soft tissues and bones. The work aimed to disclose the healing potential of a new type of ultrasound, ultra-wideband low-intensity mechanical waves (UMUS), and to compare its effects with those of low-intensity pulsed ultrasound (LIPUS) in a model of trauma.</jats:p> </jats:sec> <jats:sec> <jats:title>Material and methods</jats:title> <jats:p>The work was performed on 2-to 3-month-old male Wistar rats. The model of tail amputation was created, and a transducer emitting UMUS (1-7 MHz, 0.22 mW/cm2) was applied daily for 10 days to the surface of the trauma site in animals that were timely immobilized. LIPUS (1.5 mHz, 30.0 mW/cm2) was used in a separate group of animals. Sham-stimulated rats were used as a control. The intensity of collagen expression in the subdermal tissue was assessed in van Gieson-stained sections, whereas in the UMUS group, expression of CD31, CD34, VEGF, and Ki67 was analyzed.</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Starting on the 20th day after trauma, UMUS-treated animals demonstrated a statistically significant decrease in the surface area of the traumatic zone compared to the control, whereas LIPUS-treated rats showed this difference on the 30th day of observation. Starting from the 30th day, a significantly greater reduction in the surface of trauma was observed in UMUS, with complete closure achieved in 6 out of 9 rats (P=0.019 vs control), whereas in LIPUS-treated animals, a similar result was observed in 2 out of 8 rats (P&gt;0.05). In UMUS-treated rats, heightened expression of collagen in animals with LIPUS exceeded control data by 7.84% (P=0.034), while the expression in rats with UMUS exceeded data in LIPUS-treated rats by 14.71% (P=0.013). Increased expression of CD31, CD34, VEGF, and Ki67 was observed in UMUS-treated rats.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>UMUS treatment accelerated healing and reduced wound size, and increased the expression of collagen, CD31, VEGF, CD34, and Ki67, supporting angiogenesis and collagen formation. Effects are more pronounced compared to LIPUS treatment.</jats:p> </jats:sec> <jats:sec> <jats:title>Graphical abstract</jats:title> <jats:fig id="ufig1" position="float" fig-type="figure" orientation="portrait"> <jats:graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="717366v1_ufig1" position="float" orientation="portrait"/> </jats:fig> </jats:sec>