# Wound Dressing Materials: Bridging Material Science and Clinical Practice
## 1 Introduction  
The skin is the human body's largest organ and comprises different tissue types [1]. These tissues form a multifunctional organ that provides sensory, thermoregulatory, biochemical, metabolic, immunological, and physical protective functions [2]. Skin plays a crucial role in wound healing and infection prevention due to its unique properties. One of its key features is its ability to maintain low moisture content, which helps prevent the growth of harmful microorganisms. This moisture balance is important for creating an environment where wounds can heal without fostering bacterial growth. Additionally, the skin's acidic pH provides an inhospitable environment for pathogens, as most bacteria thrive in neutral or slightly alkaline conditions. This acidity, combined with the skin's high salt concentration, further helps to inhibit bacterial colonization and supports the skin's natural defense mechanisms. Lipids, which are abundant in the skin, also contribute significantly to wound healing. These molecules form a protective barrier that not only prevents the loss of moisture but also limits the entry of harmful pathogens. Furthermore, the skin contains over 20 antimicrobial peptides that act as natural antibiotics, attacking and neutralizing potential infections. These peptides are part of the innate immune system and play an essential role in the skin's ability to defend against microbial invaders. Together, these properties (low moisture, acidic pH, high salt levels, lipids, and antimicrobial peptides) work synergistically to support wound healing while reducing the risk of infection [1; 3]. Skin plays a critical role in protecting against pathogenic contamination and infection development. However, when the skin's normal microbiological balance is disrupted, a process called dysbiosis, these bacteria become the source of infection [4; 5]. Chronic wounds are defined as wounds that fail to heal and remain in the inflammatory phase for an unpredictable duration. They represent a significant global health issue, reaching epidemic proportions and imposing a substantial financial burden on healthcare systems [6]. Chronic wounds can have several origins such as pressure sores, diabetic ulcers, and venous ulcers, cause persistent pain, reduce quality of life, impair patient mobility, and, in some cases, result in amputations [7]. The recovery of acute or surgical wounds follows a well-coordinated series of steps aimed at restoring the skin's structure and function. Initially, the process begins with coagulation, where blood clots form to stop bleeding and provide a temporary barrier. This is followed by inflammation, where immune cells clear away debris and pathogens, preparing the wound for healing. Next, cell proliferation occurs, in which new cells are produced to close the wound and rebuild tissue. Matrix repair follows, involving the production of extracellular matrix components that provide a scaffold for tissue regeneration. Epithelialization then takes place, where new skin cells migrate across the wound to restore the outer layer. Finally, remodeling occurs, where the newly formed tissue is strengthened and refined, improving the overall integrity and function of the skin over time. Each of these steps is essential to ensure that the wound heals efficiently and that the skin's normal structure and function are re-established [8]. Chronic wounds, on the other hand, do not follow the normal physiological healing stages within a specific period. The most common types of chronic wounds are diabetic foot ulcers, pressure sores, venous leg ulcers, and arterial leg ulcers [7]. A wide range of wound dressings on the market are designed to preserve moisture within the wound to optimize skin regeneration, protect against infections, and prevent disruption of the wound bed. To promote the healing of chronic wounds, bioactive wound-healing polymers such as hydrocolloids, hydrogels, foams/films, etc., have been developed.