**1. Introduction**

The occurrence of wound is a cause of break in the skin that generally results from physical, mechanical, and thermal damage, or medical surgery and physiological disorder [1]. It

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

accompanies cell death, destruction of extracellular connective tissue components, and loss of blood vessel integrity [2]. Wound healing is a dynamic process including inflammatory, proliferative, and remodeling phases. Each phase involves numerous biochemical activities and is overlapped with other phases until the completion of wounded‐tissue regeneration [3]. When serious tissue injuries can hardly heal themselves, human interventions are required [4]. The use of wound dressings is such a first step of human interventions to first contribute the hemostasis and prevent wound from deteriorating. Wound dressings are materials generally made of gauze, synthetic, and natural polymers that are able to control moisture content, provide gaseous permeability, protect wound from microorganism, absorb exudates, exhibit low adherence, and provide compression to minimize edema as well as a temporary substrate for tissue cells to grow [1, 5]. Different types of wound need separate wound dressings exhibiting different functions according to various healing objectives. In order to obtain optimal healing result, wound dressings containing integrated functions such as antibacterial and anti‐inflam‐ matory properties, and contribution to skin‐tissue regeneration are highly desired.

Inorganic materials generally used in wound healing can be selected from a wide range of materials, such as silicone‐based bioglasses. Most of them exhibit either high‐elastic module satisfying the mechanical requirement of skin tissue or certain biodegradability to release beneficial elements for wound care, such as borate or siloxane bioglasses [6, 7]. Polymeric materials are contributed to most of wound‐dressing materials because of their processibility, moldability, low toxicity, biocompatibility, and low cost [8]. Both synthetic and natural polymers can be used to prepare appropriate wound dressings. Some typical synthetic polymers, such as polypropene (PP) and polylactic acid (PLA), although showing excellent molding ability and certain biodegradability, present inadequate biocompatibility and unpleasant side effects [9–13]. Naturally generated polymers are derived from biomacromo‐ lecules such as alginate, chitin/chitosan, gelatin, heparin, collagen, chondroitin, fibrin, keratin, silk fibroin, and bacterial cellulose (BC), and most of them show desirable properties of biocompatibility, biodegradability, nontoxicity, fluid exchange, and moldable prototypes during the synthetic process [14–20], although some unavoidable defects, such as high cost, inappropriate mechanical properties, and untunable biodegradability, are still present [14, 21]. Therefore, blending or compositing synthetic polymers with natural polymers using facile but advanced technologies [22] is highly recommended to integrate advantages of both synthetic and natural polymers and minimize their disadvantages for wound care and other medical uses.

Chitosan is the deacetylated derivative of chitin that is a linear polysaccharide composed of β‐1,4‐D glucosamine and β‐1,4‐D‐N‐acetylglucosamine [23]. Due to numerous amino groups, chitosan becomes a significant polysaccharide carrying positive charges. Such a character offers chitosan an impressive antibacterial property because negatively charged cytoplasmic membrane is neutralized by positive charge which leads to the destruction of the function of bacterial cell membrane [24]. Meanwhile, many studies have also demonstrated the effective‐ ness of chitosan in wound care that specifically exhibits merits in providing the hemostasis, accelerating the fibroblastic synthesis of collagen, and promoting the tissue regeneration [25]. Due to relatively high cost and difficulties in fiber/film forming as compared to the traditional gauze‐type wound dressing, incorporating chitosan as one of active components of wound care into cheap and easily processible material substrates has become an alternative to prepare wound dressing. The typical examples are electrospinning chitosan with polyethylene oxide (PEO) [26], polyvinyl alcohol (PVA) [27], and (PLA) [28], respectively, for antibacterial application and scaffold construction to promote tissue regeneration. Additionally, blending chitosan with other biomacromolecules, such as collagen [29], pullulan [30], and BC [31], can synergetically contribute to the enhancement of biocompatibility and reduce the toxicity of chitosan to normal tissue cells.

Aloe (*Aloe vera*) is a succulent plant and its extracts mainly consisting of carbohydrates and glycoproteins have been found to contribute to the anti‐inflammatory and wound‐healing activity [32]. The most beneficial effect of Aloe extracts (AEs) is its function in healing burned wound in which the instant reduction of painful feeling may be easily attained [33, 34]. In addition, AE can be added as a bioactive agent to other material substrates and combine other bioactive agents such as curcumin to exert a synergistic function of moisture maintenance, antibacterial, and anti‐inflammation, and thereby promote the wound healing [35]. Nowadays, AE has been successfully commercialized and found in many consumer products for either cosmetic or medicinal purposes.

Although the combination of CS and AE has shown the advantage in wound healing, the effectiveness of modified chitosan combining AE as bioactive agents of wound healing incorporated into PVA matrix has not been investigated yet. Therefore, we aimed to develop such a multifunctional wound‐dressing composite consisting of PVA, AE, and quaternary ammonium chitosan salt (QCS, 3‐chloro‐2‐hydroxypropyl trimethylammonium chloride‐ functionalized chitosan) which was expected to exhibit antibacterial property, ability of moisture maintenance, and good biocompatibility for the growth of skin tissue. Three different mass ratios of QCS, AE, and PVA were selected to investigate the effectiveness of wound‐ dressing composites prepared. Material characterization of as‐prepared wound‐healing composites was performed to investigate the porous profile, functional groups of materials, thermal stability, and water absorbability. Cell culture study and antibacterial essay were conducted to investigate the antibacterial activity and biocompatibility in an in vitro wound‐ healing environment.
