Traditional Therapies for Skin Wound Healing

Abstract

Significance: The regeneration of healthy and functional skin remains a huge challenge due to its multilayer structure and the presence of different cell types within the extracellular matrix in an organized way. Despite recent advances in wound care products, traditional therapies based on natural origin compounds, such as plant extracts, honey, and larvae, are interesting alternatives. These therapies offer new possibilities for the treatment of skin diseases, enhancing the access to the healthcare, and allowing overcoming some limitations associated to the modern products and therapies, such as the high costs, the long manufacturing times, and the increase in the bacterial resistance. This article gives a general overview about the recent advances in traditional therapies for skin wound healing, focusing on the therapeutic activity, action mechanisms, and clinical trials of the most commonly used natural compounds. New insights in the combination of traditional products with modern treatments and future challenges in the field are also highlighted. Recent Advances: Natural compounds have been used in skin wound care for many years due to their therapeutic activities, including anti-inflammatory, antimicrobial, and cell-stimulating properties. The clinical efficacy of these compounds has been investigated through in vitro and in vivo trials using both animal models and humans. Besides the important progress regarding the development of novel extraction methods, purification procedures, quality control assessment, and treatment protocols, the exact mechanisms of action, side effects, and safety of these compounds need further research. Critical Issues: The repair of skin lesions is one of the most complex biological processes in humans, occurring throughout an orchestrated cascade of overlapping biochemical and cellular events. To stimulate the regeneration process and prevent the wound to fail the healing, traditional therapies and natural products have been used with promising results. Although these products are in general less expensive than the modern treatments, they can be sensitive to the geographic location and season, and exhibit batch-to-batch variation, which can lead to unexpected allergic reactions, side effects, and contradictory clinical results. Future Directions: The scientific evidence for the use of traditional therapies in wound healing indicates beneficial effects in the treatment of different lesions. However, specific challenges remain unsolved. To extend the efficacy and the usage of natural substances in wound care, multidisciplinary efforts are necessary to prove the safety of these products, investigate their side effects, and develop standard controlled trials. The development of good manufacturing practices and regulatory legislation also assume a pivotal role in order to improve the use of traditional therapies by the clinicians and to promote their integration into the national health system. Current trends move to the development of innovative wound care treatments, combining the use of traditional healing agents and modern products/practices, such as nanofibers containing silver nanoparticles, Aloe vera loaded into alginate hydrogels, propolis into dressing films, and hydrogel sheets containing honey.

Figures

Paulo J. Bártolo, PhD

Figure 1.

Classification of traditional therapies for skin wound healing. Traditional therapies and compounds are used in different phases of the healing process in a great variety of physical forms, either commercially available or under investigation, stimulating the skin regeneration process. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/wound

Figure 2.

Influence of fibroin/aloe gel film dressings on the wound healing of normal rat and streptozotocin-induced diabetic rat. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/wound

Figure 3.

(A) Free maggots suspended in isotonic saline solution before application onto the wound. (B) Biobag that contains maggots inside and a sponge to prevent the net to collapse. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/wound

Figure 4.

(A) Maggots before the application into a chronic wound, and maggots in direct contact with the wound at the end of the treatment, during the removal. (B) The experimental scheme used to test the effect of the delivery of maggot extract from a hydrogel wound dressing onto model wounds in monolayer cell culture. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/wound

Figure 5.

Processing steps in the fabrication of PMMA nanofibers that contain silver nanoparticles through radical-mediated dispersion polymerization. Macroscopic image of Ag+/PVA aqueous solution (A) and transmission electron microscopy images of Ag/PVA linear assembly (B) and Ag/PMMA nanofiber (C). AIBN, 2,2-Azobis(isobutyronitrile); MMA, methyl methacrylate; PMMA, poly(methyl methacrylate); PVA, poly(vinyl alcohol). To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/wound