Comparative Analysis of the Effectiveness of Some Biological Injected Wound Healing Stimulators and Criteria for Its Evaluation

PURPOSE

To investigate the comparative effectiveness of certain biological injectable stimulants for the healing of skin wounds and criteria for its assessment.

MATERIALS AND METHODS

A comparative study of the effectiveness of mesenchymal stem cells (SC group), collagen (Collagen group), and deproteinized calf blood hemoderivative (DCBH group) was carried out using an acute wound model. Control wounds were injected with isotonic sodium chloride solution (Control group). A total of four groups (28 wounds per group) were included in the study. Aged male Wistar rats were used as experimental animals. A dynamic assessment of the wound areas and edges, microvasculature assessment via laser Doppler flowmetry, histological and morphometric analyses to determine the quantitative and qualitative fibroblasts composition, as well as the degree of newly synthesized collagen maturity, was conducted on days 0, 3, 7, and 14.

RESULTS

The administration of SCs provided a rapid but short-lasting effect, whereas the administration of collagen resulted in a delayed but long-lasting wound-healing effect. DCBH resulted in little to no effect. An increase in the perfusion volume of the wound edges accelerated the regeneration process, while the level of microcirculation did not affect the number and activity of fibroblasts. The wound healing acceleration, as well as the new collagen and stratified epithelium formation and maturation, was associated with the presence of a sufficient pool of mature and active fibroblasts in the wound, and not with the number of fibroblasts.

CONCLUSION

The present results clarify the action mechanisms of the studied drugs. In addition, the application purposes and different effects of each drug on the different wound healing phases were demonstrated. An assumption on the multi-component treatment advisability under the wound condition objective assessment possibility was made. Findings from this study may assist clinicians in making an informed transition to personalized wound management and achieve better clinical outcomes.

The Effect of Inflammation on the Healing Process of Acute Skin Wounds Under the Treatment of Wounds with Injections in Rats

PURPOSE

To study the effects of inflammation on the healing process of rats' acute skin wounds during treatment with different injections.

METHODS

The study was carried out on Wistar rats, on which square wounds were simulated in the back region. Four groups of wounds were studied. On the day of the simulation (day 0), solutions of the drugs were injected into the wounds: an isotonic sodium chloride solution (Control group), mesenchymal stem cells (SC group), collagen (Collagen group), and a deproteinized hemoderivative of calf blood (DHB group). Within 2 weeks, the wound healing process was assessed by observing and calculating changes in the wound areas, temperatures, and epithelialization levels. On days 3, 7, and 14, wound tissue samples were taken for histological examination, morphological analysis of the healing process, and quantitative assessment of granulation layers' leukocyte infiltration.

RESULTS

A correlation between the process of inflammation and epithelization during the healing of skin wounds was established. The anti-inflammatory effect of SC injection on the wound edge tissues was determined, as well as the pro-inflammatory effect of DHB, and the absence of effects on the inflammation course under the collagen treatment. Compared to the control group, the transition from the exudative phase of inflammation to the proliferative phase was faster, as well was wound epithelialization in the SC and Collagen groups. A negative correlation between the level of tissue temperature in the center of wounds and their area were recorded, which intensified over time.

CONCLUSION

The severity and duration of the inflammation process during wound healing were ambiguous with the use of different injection treatments. This should compel clinicians to use different markers of drug therapy effectiveness during wound healing. Excessive leukocyte infiltration with a low temperature of wounds and a large scab were markers of delayed wound healing.

[Mechanisms of the wound-healing action of native collagen type I in ischemic model full-thickness skin wounds on the example - medical devices Collost «(part I)]

Active collagen type I successfully used in regenerative medicine. However, despite the large amount of material of cellular and molecular mechanisms underlying skin repair, the molecular mechanisms of wound healing with use collagen type I, not studied enough.

PURPOSE OF THE STUDY

To study the mechanism of the native collagen type I wound-healing action of native type I collagen on the example of the medical device Collost (7% gel) in a model of the rats difficult-to-heal skin wounds.

MATERIAL AND METHODS

Male rats in population SD (72 individuals) surgically formed an ischemic dorsal skin flap (3×10 cm) with two full-thickness skin wounds 6 mm in diameter.The trained animals divided into 2 groups: in the experimental group, medical device Collost (gel) applied once after the operation, in the control group - a standard medical device for comparison. The dynamics of wound healing assessed, the number of M2 macrophages, myofibroblasts, vascularization and expression of the main markers of the repair process in the wound tissues and time points for assessment were: after 3, 7 and 14 days after operation using macroscopic, immunohistochemical, and molecular methods.

RESULTS

It has been established that the mechanism of action of native collagen type I is associated with the acceleration of the appearance of «progenitorous» M2-macrophages in the wound tissues, decrease in the severity of inflammation or reduction in the duration of the inflammatory stage of the repair process, change in the expression spectrum of number of growth factors, an acceleration of neovasculogenesis.

CONCLUSION

In this work, on the modern experimental model shown regenerative efficiency of a medical device based on collagen type I and described the molecular and cellular processes of wound healing when using it It has been shown that the acceleration of wound healing processes occurs when using a medical device based on native collagen type 1, it is also accompanied by a better aesthetic closure of the damaged skin area.