The fundamental skin role is to supply a supportive barrier to protect body against harmful agents and injuries. Three layers of skin including epidermis, dermis and hypodermis form a sophisticated tissue composed of extracellular matrix (ECM) mainly made of collagens and glycosaminoglycans (GAGs) as a scaffold, different cell types such as keratinocytes, fibroblasts and functional cells embedded in the ECM. When the skin is injured, depends on its severity, the majority of mentioned components are recruited to wound regeneration. Additionally, different growth factors like fibroblast growth factor (FGF), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) are needed to orchestrated wound healing process. In case of large surface area wounds, natural wound repair seems inefficient. Inspired by nature, scientists in tissue engineering field attempt to engineered constructs mimicking natural healing process to promote skin restoration in untreatable injuries. There are three main types of commercially available engineered skin substitutes including epidermal, dermal, and dermoepidermal. Each of them could be composed of scaffold, desired cell types or growth factors. These substitutes could have autologous, allogeneic, or xenogeneic origin. Moreover, they may be cellular or acellular. They are used to accelerate wound healing and recover normal skin functions with pain relief. Although there are a wide variety of commercially available skin substitutes, almost none of them considered as an ideal equivalents required for proper wound healing.

Wound healing is a complex process with the considerable burden on healthcare system. There are several cellular therapy methods that have been introduced to treat different types of wounds. Despite the advantages of cellular therapy, it is needed to overcome different limitations of this method such as; tumorigenicity and immune rejection. Accordingly, scientists have suggested cell-based vesicles and exosomes. Exosomes can promote proliferation, migration, and angiogenesis process in the wound environment. They have also some advantages such as the potential for drug and gene delivery, easy to storage, and stability in the body. These advantages make them as a novel approach in regenerative medicine without the limitations of cellular therapy. In this review, the authors emphasize on biological properties of MSC-exosomes and their therapeutic effects as a new strategy for wound regeneration.

Skin as the outer layer covers the body. Wounds can affect this vital organ negatively and disrupt its functions. Wound healing as a biological process is initiated immediately after an injury. This process consists of three stages: inflammation, proliferation, remodeling. Generally, these three stages occur continuously and timely. However, some factors such as infection, obesity and diabetes mellitus can interfere with these stages and impede the normal healing process which results in chronic wounds. Financial burden on both patients and health care systems, negative biologic effect on the patient's general health status and reduction in quality of life are a number of issues which make chronic wounds as a considerable challenge. During recent years, along with advances in the biomedical sciences, various surgical and non-surgical therapeutic methods have been suggested. All of these suggested treatments have their own advantages and disadvantages. Recently, cell-based therapies and regenerative medicine represent promising approaches to wound healing. Accordingly, several types of mesenchymal stem cells have been used in both preclinical and clinical settings for the treatment of wounds. Adipose-derived stromal cells are a cost-effective source of mesenchymal stem cells in wound management which can be easily harvest from adipose tissues through the less invasive processes with high yield rates. In addition, their ability to secrete multiple cytokines and growth factors, and differentiation into skin cells make them an ideal cell type to use in wound treatment. This is a concise overview on the application of adipose-derived stromal cells in wound healing and their role in the treatment of chronic wounds.

Tissue and organ transplantation is one of the most promising treatments for some incurable diseases. Nowadays, transplantation is the common therapy in many countries. Unfortunately, availability of donated tissues and organs is limited. There are several factors which may affect donation rate for instance; social factors, culture, religion, and family decision. Accordingly, religious beliefs have a crucial role in tissue and organ donation and transplantation. Islam as a code of life has a comprehensive road map to lead mankind. Spiritual view of human life is considered to be much more valuable in Islam. Therefore, saving a human life is one of the most important Islamic teachings. In Iran as a Muslim country, tissue and organ transplantation program was established based on religious scholars' permission which has an essential role towards considerable development of the program in Iran.

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