Factors affecting skin keratinocyte and fibroblast extraction yields for the production of living skin substitutes to treat severely burned patients.

Abstract

As autografting is limited for severely burned patients due to a lack of healthy donor sites, tissue-engineered autologous skin substitutes have emerged as a promising alternative. Yet, challenges persist, particularly regarding production time. Since cell culture is influenced by multiple factors, identifying these factors is crucial for improving culture yields. This retrospective study aimed to identify factors affecting skin cell extraction yields. Culture data (method used, etc.) and clinical data (medical history, etc.) from all available patient records over a 35-year-period were collected. 18 variables were assessed using XGBoost as a variable selection tool, before fitting mixed-effects multivariate linear modeling. As expected, age inversely correlated with keratinocyte and fibroblast extraction yields, decreasing by 0.048 × 10⁶ cells/cm² per year (CI_95 % = [-0.065;-0.031]) and 0.035 × 10⁶ cells/cm² per year (CI_95 % = [-0.050;-0.019]), respectively. Keratinocyte yield also rose by 0.936 × 10⁶ cells/cm² (CI_95 % = [0.175;1.697]) when hairs could be grasped during the epidermis-dermis separation. Conversely, fibroblast yield increased by 0.042 × 10⁶ cells/cm² per day post-burn (CI_95 % = [0.007;0.076]) and by 0.019 × 10⁶ cells/cm² per percentage of TBSA burned (CI_95 % = [0.002;0.036]). This findings provide valuable insights into factors influencing skin cell extraction yields, which may help optimize skin biopsy parameters, ultimately improving production efficiency.