## 3 Results
### Immunohistochemistryal Analysis  
During the next stage, the dynamics of the following WP markers were studied: collagen types 1 and 3; VEGF (vascular endothelial growth factor); and SMA (smooth muscle actin), which is a marker expressed by vascular smooth muscle elements and myofiblasts. The rise in the level of these indicators is considered as a reliable criterion for the activation of WP. The dynamics of wound repair markers in clinical groups is shown in Figure 9.  
An analysis of wound repair markers showed that before treatment, collagen types 1 and 3 in the bottom and edges of the pressure ulcer were found in the extracellular matrix only in the form of minor deposits of amorphous structures without the formation of fibers; minimal expression of VEGF in the endothelium of a few vessels (15% of wound stromal cells), and SMA (15% of wound stromal cells) (Figure 9 and Table 2). On the 14 th day after the start of complex treatment using LTP technology, a moderate increase in the amount of type 1 and 3 collagens (up to four points each) was detected in the bottom and edges of the pressure ulcer, which form clear fibrous structures in the extracellular matrix. At the same time, a higher content of collagen cells was noted in the edges of the DU compared to the bottom (Figure 9 and Table 2).  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Collagen 1** & **Collagen 3** & **VEGF (\%** & **SMA (\%** \\  & **(In Points)** & **(In Points)** & **Positive Wound** & **Positive Wound** \\  & & & **Stromal Cells)** & **Stromal Cells)** \\ \hline Experienced group & 0 & 0 & 15.0 \(\pm\) 0.5 & 10.0 \(\pm\) 1.0 \\ before treatment & & & & \\ Experimental group & 4.0 \(\pm\) 0.3 * & 4.0 \(\pm\) 0.3 * & 30.0 \(\pm\) 1.5 * & 60 \(\pm\) 2.0 * \\
14 days after treatment & & & & \\ Experimental group & 6.0 \(\pm\) 0.5 * & 6.0 \(\pm\) 0.5 * & 70 \(\pm\) 2.0 * & 30.0 \(\pm\) 1.2 * \\
30 days after treatment & & & & \\ Control & 0 & 0 & 12 \(\pm\) 0.5 & 15.0 \(\pm\) 1.0 * \\ \hline \hline \end{tabular}  
* \(p<\) 0.05.  
\end{table}
Table 2: Average values of marker expression in wound tissue before and after treatment.  
In the bottom and edges of the ulcer, there was an increase in the expression of the marker VEGF compared with the initial stage--to a moderate level, especially in the endothelium of capillary-type vessels, the number of which also increased (30% of wound stromal cells). The amount of the SMA marker also increased compared to the pretreatment stage (60% wound stromal cells). At this intermediate stage, the highest expression of the marker was noted.  
A month later, on the 30 th day from the start of complex treatment, a moderate increase in the amount of collagen was detected in the bottom and edges of the pressure ulcer (up to six points each), which formed clear fibrous structures in the extracellular matrix. A markedly higher content of collagens was observed in the edges of the bedsore compared to the bottom. The level of collagen content was comparable to the 14 th day of treatment.  
Marker expression VEGF in the vascular endothelium of the bottom and edges of the pressure ulcer was higher compared to the 14 th day of treatment (70% of wound stromal cells). The number of capillaries also increased.  
The dynamics of SMA marker expression by day 30 was also positive compared to the starting point, but somewhat worse when compared to the intermediate control point (day 14 of therapy) (30% of wound stromal cells).