A 58-year-old man with poorly controlled diabetes mellitus (HbA1c 9.8%) presents with a chronic non-healing ulcer on his right foot for 3 months. The ulcer base is pale, granular, and shows minimal bleeding on gentle probing. Histopathology reveals sparse fibroblasts, reduced angiogenesis, and thin, disorganized collagen fibers. Which of the following is the PRIMARY mechanism by which hyperglycemia impairs wound healing in this patient?