The skin is the
biggest organ of the human being and has many functions. Therefore, the healing
of a skin wound displays an extraordinary mechanism of cascading cellular
functions which is unique in nature. As healing and regeneration processes take
place in all parts of the human body, this review focuses on the healing
processes of the skin and highlights the classical wound healing phases. Regeneration
describes the specific substitution of the tissue, for example; the superficial
epidermis, mucosa or fetal skin meanwhile skin repair displays an unspecific
form of healing in which the wound heals by fibrosis and scar formation (Reinke & Sorg, 2012).
A wound is defined as a defect or a break in the skin,
resulting from physical or thermal damage or as a result of the presence of an
underlying medical or physiological condition (Nidhi, Indrajeet, Khushboo, Gauri, & Sen, 2011).
Wound healing is a complicated process, dependent on the
patient’s underlying health and nutritional status and also upon the
clinician’s ability to recognize stages of wound healing (Enoch, Leaper, & Beldon, 2010). Wound healing is a complex
series of reactions and interactions among cells and “mediators. Many
intrinsic and extrinsic factors affect wound healing. Wound healing has
traditionally been divided into three distinct phases: inflammation,
proliferation, and remodelling(Broughton, Janis, & Attinger, 2006).
Wound dressings play a crucial role in the healing of
certain types of open, unless the moist, warm and nutritious environment of
wound beds provides an ideal condition for microbial growth. Therefore, the
wound healing process can be interfered by bacterial colonization and
subsequent infection, which may cause an excessive and prolonged inflammatory
response from the host tissues (Moraes et al., 2016).
Hydrogels are macromolecular networks able to absorb and release water
solutions in a reversible manner, in response to specific environmental
stimuli. Such stimuli-sensitive behaviour makes hydrogels appealing for the
design of ‘smart’ devices, applicable in a variety of technological fields. In
particular, in cases where either ecological or biocompatibility issues are concerned,
the biodegradability of the hydrogel network, together with the control of the
degradation rate, may provide additional value to the developed device (Sannino, Demitri, & Madaghiele, 2009).