FN1 and diabetes mellitus: Wound-healing deficits associated with diabetes are diverse, multifactorial, complex, and interrelated [30] and are believed to be caused by impaired blood flow and impaired oxygen release due to increased blood sugar, decreased collagen, and fibronectin synthesis due to protein malnutrition, impaired local immune, and cell defenses and decreased anabolic activity with decreased levels of insulin and growth hormone.