Morphological features of skin scars on the background of treatment with autologous adipocytes

Abstract

So far the pathogenesis of changes and reconstruction of recipient tissues after transplantation of autologous adipocytes have not been studied sufficiently. The purpose of the research was to carry out the estimation of efficiency and morphological grounding of the surgery of transplanting autologous adipocytes for treating skin scars. The study included 35 patients (12 males and 23 females at the age of 18-55 years) with skin scars after deep burns. The majority of patients were with atrophic scars – 25 (71.4%); with hypertrophic – 8 (22.9%); with normotrophic – 2 (5.7%). To verify the processes in scar tissues the histological biopsy examination of the scar tissue was carried out; the samples were taken from patients with post-burn skin scars before and after the operation of transplanting autologous adipocytes. Sections were studied and pho­tographed under the microscope Zeiss "Primo Star", photocamera DCM 500. To verify the mechanism of action of autoadipocytes on the reparative processes in the scar tissues, biopsy of 11 patients with atrophic scars was studied, with immunohistochemical methods  of determining CD-34 + - cells with the help of monoclonal mouse antibodies to CD-34 (clone QBEnd/10) and determination of Ki-67– antigen in the nucleus of cells in all phases of the cellular cycle, except for G0 which was studied with the help of monoclonal rabbit antibodies (clone SP6), Thermo Scientific, USA. The carried out research has shown that after transplantation of autologous adipocytes in patients with post-burn scars, the process of tissue reconstruction starts in the recipient area. On the 12^th and 21^st day after the operation in areas of hyalinosis there was “discementing” and “separation” of collagen fibers, which may testify in favor of the probable lysis of the smallest dense hyaline deposits by the enzymes of the transplanted autologous adipocytes, in particular by lipoproteinlipasa. Thus there was a release of the skin fiber structures from lipoproteins of the blood plasma, the drainage function of the stroma and circulation of the tissue fluid were restored, intercellular communication was mitigated. In the tissue gaps which were freed from massive molecular deposits and polymers, capillaries were formed. Thus the total number of CD34 + - elements in biopsy before the operation on average was 39.3±7.3 (p<0.01), on the 14th day after the operation this indicator increased up to 53.5±11.0 (p<0.01), and on the 21^st day it reached 83,4+22,8 (p<0.01), that is it has increased twice in comparison with the values before the operation.Accordingtotheresultsofthe immunohistochemicalresearch oftheproliferativeactivityof Ki-67 cellsinallcasesthepositivereactionwasobservedexclusivelyin cells of the basal multi-layered keratinized squamous epithelium, cells of glandular and peloid appendages of skin. Inthe areaswheretherewereCD34 + - elementsamong the bundles of collagen fibers, reaction with Ki-67 was negative. Onlyinscarbiopsyonthe 21^stdayaftertheoperation, inhypodermthereweresingularepithelioidcellsneargapswithextracellularfatwhichhad Ki-67+ reaction.The increase in the number of endothelium and other CD34+ elements testifies in favor of transformation of the transplanted autologous fat cells in endothelium and other CD34+ cells.