Dispersed allogeneic biomaterials for the prevention of cicatricial complications during limb replantation (research study)
Authors:   Bashkir State Medical University, Ufa, Russian Federation, Muslimov S.A. , Ibragimov R.K. ,   Bashkir State Medical University, Ufa, Russian Federation,   "Masterskaya Krasoty +” LLC, Ufa, Russian Federation, Lebedeva A.I. ,   Bashkir State Medical University, Ufa, Russian Federation
Published: June 2024

Aim: during research study, to identify the nature of cicatricial changes after limb replantation and to study the possibility of preventing fibrosis using an allogeneic biomaterial. Materials and Methods: the research was conducted on 48 male rats (24 each in the control and experimental groups). The operation consisted of a circular incision of soft tissues in the middle third thigh, followed by microvascular stitches of blood vessels, nerves, muscles and skin. In the experimental group, a dispersed allogeneic biomaterial (DAB), which is a sterile powder prepared from decellularized connective tissue, was applied to wound surfaces before stitching. The subjects were withdrawn from the study 7, 14, 30 and 90 days after surgery. Tissue samples from the surgical area were subjected to histology and immunohistochemistry: the expression of transforming growth factor (TGF-β1), tumor necrosis factor (TNF-α), antigen of the main histocompatibility complex (HLA-DR), myosatellitocyte marker (MyoD) was evaluated. Results: in the control group 90 days after surgery, fibroblastic sleeve was found around the vessels and nerves, as well as fibroblast foci between the stitched muscles, therefore, a typical picture of aseptic inflammation. This process was accompanied by high TGF-β1 and HLA-DR expression with low TNF-α expression. In the experimental group, DAB particles were biodegraded by macrophages and resorption. Fibrous membranes around the stitched vessels and nerves consisted of collagen fibers thinner than in the control group. Cicatricial changes were not detected at the sites of muscle stitching. At a later date (30 and 90 days), the vessels and nerves were surrounded by thin collagen fibers. TNF-α expression significantly exceeded that in the control group, while the TGF-β1 and HLA-DR expression remained at a low level. Given time (90 days), a defect cicatrization and a decrease in these cytokines expression were detected in both groups. Starting from the 14th day of the study, MyoD+myosatellitocytes were detected in the subjects of the experimental group, which indicated the muscle fiber regeneration. No MyoD+cells were detected in the subjects of the control group during the study. Conclusion: conducted study showed that aseptic inflammation occured during limb replantation, in the proliferative phase of which fibroblastic sleeve formed around stitched vessels and nerves, as well as fibroblast foci between fragments of stitched muscles, accompanied by high TGF-β1 and HLA-DR expression. The DAB allows to change the wound process course due to the macrophages activation of the proinflammatory phenotype, which is manifested by a significantly higher TNF-α expression, correlating with low TGF-β1 and HLA-DR expression. Under these conditions, vascular fibrosis is inhibited and damaged muscle fibers are regenerated. Thus, the DAB use in limb replantation helps to prevent vascular fibrosis and stimulate progenitor muscle cells. KEYWORDS: replantation, inflammation, fibrosis, allogeneic biomaterial, macrophages, TGF-β1, TNF-α, HLA-DR, myosatellitocytes, MyoD. FOR CITATION: Muslimov S.A., Ibragimov R.K., Lebedeva A.I. Dispersed allogeneic biomaterials for the prevention of cicatricial complications during limb replantation (research study). Russian Medical Inquiry. 2024;8(4):201–207 (in Russ.). DOI: 10.32364/2587- 6821-2024-8-4-3.