During the maturation/remodeling phase of wound healing, which factor can impair it?

• A. Excessive scar tissue
• B. Infection
• C. Hypoxia
• D. Necrotic tissue

Answer: (C)

During maturation/remodeling, the wound refines its initial collagen matrix, replacing type III with stronger type I and increasing tensile strength through cross-linking. This process requires adequate oxygen because enzymes that hydroxylate collagen (proline and lysine residues) and the cross-linking enzyme lysyl oxidase depend on O2 to function. If tissue is hypoxic, these steps slow or fail, collagen maturation is impaired, and the wound remains weaker and slower to remodel. While infection or necrotic tissue can affect healing by sustaining inflammation, hypoxia specifically disrupts the biochemical maturation of the collagen matrix, making it the factor most likely to impair this phase.