Cell and Organ Transplantology. 2024; 12(2):110-117 (e2024122171)
DOI: 10.22494/cot.v12i2.171

The effect of human umbilical cord-derived mesenchymal stem cell transplantation on reparative processes during the reconstruction of muscle-aponeurotic defects of the anterior abdominal wall in rats

Varvaruk M-I., Dovgalyuk A., Dzubanovsky I., Holovata T., Shevchuk O.

• I. Horbachevsky Ternopil National Medical University, Ternopil, Ukraine

Abstract

Postoperative ventral hernias represent a serious challenge in modern surgery, arising as complications after abdominal surgeries due to weakness or defects in the musculo-aponeurotic structure of the anterior abdominal wall. Mesenchymal stem cells (MSCs) exhibit high reparative potential due to their ability to paracrinally stimulate the regeneration of damaged recipient’s tissues.
Objective. To establish the effect of intraperitoneal transplantation of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) on the regeneration of muscle fibers in the area of musculo-aponeurotic defect reconstruction of the anterior abdominal wall in rats.
Materials and methods. A surgical model of a musculo-aponeurotic defect (2 cm in diameter) of the anterior abdominal wall was created in 72 white rats. The animals were divided into four groups depending on the method of defect reconstruction:1 – reconstruction using autologous tissue; 2 – reconstruction using autologous tissue combined with MSC injection; 3 – reconstruction using a polypropylene mesh; 4 – reconstruction using a polypropylene mesh combined with MSC injection. hUC-MSCs were isolated from umbilical tissue using an enzymatic method. The expression of surface markers validated using flow cytometry. hUC-MSCs were administered intraperitoneally at a dose of 1 million cells per kg of body weight. On the 10^th and 30^th days, histological sections of anterior abdominal wall tissues in the area of the musculo-aponeurotic defect reconstruction were analyzed for the presence of granulation tissue, collagen fibers, newly formed connective tissue, and cellular infiltration. Morphometric analysis was performed to compare the relative areas of granulation and fibroreticular tissue, microcirculatory vessels, and the number of neutrophilic leukocytes, lymphohistiocytic elements, and fibroblasts per mm² of the section area.
Results. In Group 1, loose connective tissue rich in fibroblasts and histiocytes was observed in the area of reconstruction. In Group 2, a significantly lower intensity of the cellular response was noted, combined with the formation of denser connective tissue bundles; in the areas of muscle fiber damage, cross-striations were more distinctly visualized. On the 10^th day, the area of granulation tissue was 34.6 % smaller, and the area of microcirculatory vessels was 15.9 % smaller compared to the first group and 28.1 % and 57.2 %, respectively, compared to Group 3 at the same time point. In Group 3, granulation tissue formed in areas of necrosis and muscle fiber destruction. The best results were obtained in Group 4 (polypropylene mesh with MSCs), where complete resolution of the inflammatory response and scar tissue formation were observed. On the 10^th day, the granulation tissue area in Group 4 was 2.5 times smaller compared to the first group, 1.3 times smaller compared to Group 2 and 2.5 times smaller compared to Group 3. The relative area of microcirculatory vessels in Group 4 was 1.8 times smaller compared to Group 1, 1.3 times smaller compared to Group 2, and 1.8 times smaller compared to Group 3. The relative area of fibroreticular tissue was 3.2 times larger compared to Group 1, 1.2 times larger compared to Group 2, and 2.3 times larger compared to Group 3. The fibroblast count per mm² was higher, while the neutrophil count was lower, contributing to proper scar formation. On the 30^th day, no granulation tissue, microcirculatory vessels, or leukocytes were observed.
Conclusion. Intraperitoneal transplantation of hUC-MSCs in addition to the use of polypropylene mesh as a mean of reconstruction of musculo-aponeurotic anterior abdominal wall defect in rats enhances regeneration in the area of the modeled defect and promotes rapid healing.

Keywords: musculo-aponeurotic defect; postoperative hernias; hernioplasty; human umbilical cord-derived mesenchymal stem cells; cell transplantation

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