Figure 2.

Ideal in vitro models of wound healing disorders envisioned to reproduce clinical key aspects. (A) Chronic wounds are characterized by an impaired repair process. A prolonged inflammatory phase, hypoperfusion/ischemia, infections, and/or biofilm formation keep chronic wounds from transcending to the proliferation phase [55,56]. (B) Keloids are enlarged, raised, tumor-like scars that can even extend beyond the original margins of a wound. Keloid tissue is composed of disorganized, thick, eosinophilic collagen type I and III bundles that are randomly oriented [1]. (C) Hypertrophic scars have a red/pink color as well as an elevated and uneven surface. In contrast to keloids, they do not extend beyond the margins of the primary wound. Hypertrophic scars are characterized by the persistence of myofibroblasts, which contribute to enhanced contraction, and increased production of collagen and a-SMA [1,78,79].