Table 1.

Challenges of the wound environment

Challenge	Characteristics	Possible solutions
Mechanical	Difficulty in retaining locally delivered therapeutics during normal movements or change of dressing.	Protected delivery (i.e., patch delivery or bandage based).
Oxidative stress	Free radicals generated by uncontrolled oxidative stress can cause cellular damage and death.	Deferoxamine and other free radical scavengers have been shown to reduce oxidative stress in wounds.
Enzymatic	Proteases present during normal and pathological wound healing degrade growth factors.	Controlled and sustained release using drug-delivery systems.
Hypoxia/ischemia	Arterial or venous insufficiency impairing blood supply to injured tissue; edema impairing oxygen diffusion to injured tissue.	Hyperbaric oxygen therapy, negative pressure wound therapy, and pro-angiogenic therapeutics.
Infected/necrotic tissue	Infected tissue is chronically inflamed and unable to progress through phases of wound healing; necrotic tissue lacks the ability to heal and is prone to infection.	Debridement, systemic antibiotics, and antimicrobial dressings.