**2. Wound dressings**

Wound dressings can maintain a moist environment in the wound which helps in proliferation and migration of fibroblast and keratinocytes. Moisture in the wound serves as a transporter for enzymes, growth factors, and hormones, thus inducing cell growth. Moist wound dressings promote collagen synthesis and decrease scar formation [36] which help wounds to heal faster [37]. Modern moist wound dressings can be classified depending on their materials (synthetic and natural polymers) and physical forms (hydrogels, hydrocolloids, films, and wafers).

Hydrogels consist of hydrated polymers which make them hydrophilic in nature. Water content is higher than 95%, and as a result they cannot absorb much exudate and cause maceration. But, this dressing is very useful in dry wound which can maintain moisture within wounds [36]. A Cochrane Review [38] of hydrogel dressings for healing diabetic foot ulcers suggests that hydrogel dressings are more effective than basic wound contact dressing. Hydrogels have advantages of autolytic debridement of slough and necrotic tissue and do not support bacterial growth [39, 40]. Hydrocolloid dressings are occlusive and can absorb wound exudate into the matrix to help improve healing. It can work for a sustained period of time, thus reducing the frequency of dressing changes. It also assists autolysis of necrotic materials [40]. Due to its extra absorbent nature, it is widely used in the treatment of cavity wounds [41]. A Cochrane Review [42] reported that any type of hydrocolloid and other dressings have no difference in efficacy. Foam dressings are highly absorptive, protective, and comfortable to the body surface. They promote thermal insulation, angiogenesis, and autolysis [43]. Film dressings are adhesive, transparent, durable, comfortable, and cost effective. Due to their transparency, the wound bed can be monitored without removing the dressing. However, films are suitable for superficial pressure wounds. The disadvantage of film dressing is maceration of wound exudate [36]. Lyophilized wafers are one of the most recent moist dressings proposed for wound care. Due to their highly porous nature, they can absorb high amounts of exudate rapidly which improves wound healing. Wafers can carry both antibacterial and anti-inflammatory drugs at the same time which give dual effects of inhibiting bacteria and reducing inflammation [44]. Wafers have good adhesion and diffusion properties [45] while Labovitiadi et al. [46] reported that wafers are a compatible delivery system for both insoluble and soluble antimicrobial drugs that exhibit better antimicrobial activity.
