Current wound healing procedures and potential care

Abstract

In this review, we describe current and future potential wound healing treatments for acute and chronic wounds. The current wound healing approaches are based on autografts, allografts, and cultured epithelial autografts, and wound dressings based on biocompatible and biodegradable polymers. The Food and Drug Administration approved wound healing dressings based on several polymers including collagen, silicon, chitosan, and hyaluronic acid. The new potential therapeutic intervention for wound healing includes sustained delivery of growth factors, and siRNA delivery, targeting microRNA, and stem cell therapy. In addition, environment sensors can also potentially utilize to monitor and manage microenvironment at wound site. Sensors use optical, odor, pH, and hydration sensors to detect such characteristics as uric acid level, pH, protease level, and infection - all in the hopes of early detection of complications.

Keywords: Chronic wounds; Growth factors; Sensors; Stem cells; Wound dressings; Wound healing; siRNA.

Fig. 1

The acute wound-healing cascade. The progression of acute wound healing from hemostasis to the final phases of remodeling is dependent on a complex interplay of varied acute wound-healing events. Cytokines play a central role in wound healing and serve as a central signal foe various cell types and helaing events [8].

Fig. 2

Histopathological analysis of (A) hematoxylin and eosin (H&E) and (B) Masson’s trichrome staining of control and diabetic mouse skin, untreated or treated with MPC, NT and NT-loaded MPC foam (magnification 100×). Representative images of three skin stainings were analyzed. (a) In diabetic wounds granulation tissue is retained in the dermis with overgrowing fibroblast proliferationon day 3 post-wounding (H&E, 200×). (b) Infiltrating polymorphonuclear leukocytes and lymphocytes in the granulation tissue in control mice on day 3 post-wounding (H&E, 200×). (c) Persistent inflammatory cells (neutrophils and lympho-plasmocytic cells) in PBS-treated diabetic mice on day 10 post-wounding (H&E, 200×). (d) Fewer inflammatory cells in granulation tissue, compared with (c), in MPC-treated wounds on day 10 post-wounding (H&E, 200×). (e) Less deposition of collagen in PBS-treated diabetic mice on day 10 post-wounding (Masson’s trichrome, 200×). (f) The granulation tissue is formed mainly of thin collagen fibers parallel to the epidermis (Masson’s trichrome), [88].

Fig. 3

Release of Insulin-like growth factor-1 (IGF-1) from chitosan microparticles prepared by coacervation method at different environmental conditions [101].

Fig. 4

Schematic representation of the different wound healing phases and a summary of the most relevant micro RNAs thus far identified, that are involved in wound healing impairment in diabetes. Arrows indicate wound up-or down regulation [113].

Fig. 5

Transplanted HUCPVC accelerated wound healing. (A) Mouse excisional wound-splinting model. (B) Representative photographs of the wounds on days 7 and 14 after HUCPVC transplantation. (C) Measurement of wound closure at different time-points (HUCPVC, n = 6; hSFb, n = 6; PBS, n = 10). The percentage of wound closure was calculated as: (area of original wound – area of wound at time of analysis)/area of original wound × 100. (D – O) Histologic analysis of the wound 14 days after transplantation. (D, H, L) HE staining. (E, F, I, J, M, N) Staining with an anti-human type I collagen MAb. (G, K, O). Staining with an anti-mouse CD31 MAb. Scale bar = 100 µm. Controls were PBS-injected [130]. Data are presented as means ± SD. *P<0.05; **P< .01; ***P<0.001.

Fig. 6

Use of an EES on human subjects in a clinical setting. a) EES laminated on the skin (forearm) after sterilization. b) Microscope images of the skin with 30 separate processes of mounting and removing an EES. c) Microscope image of the skin after the medical tape removal (1) and image of the tape surface (2). d) Illustration of the materials interface between the EES and skin e) Illustration of the medical tape and skin. f) Fluorescence images of viability of skin cells grown on an EES (left) and the results of control experiments on standard cell culture materials (right). Most of the cells on the EES remain viable (“red” cells). g) Clinical setting for wound monitoring in a typical exam room. h) EES laminated on wound and contralateral (control) sites. i) Assessment sequence and estimated time [138].