**2.1. Materials**

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‐

256 Composites from Renewable and Sustainable Materials

matory properties, and contribution to skin‐tissue regeneration are highly desired.

medical uses.

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

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

Quaternary ammonium chitosan salt (QCS, 3‐chloro‐2‐hydroxypropyl trimethylammonium chloride‐functionalized chitosan, HACC‐101) was purchased from Tianhua Bioagents (Don‐ gying, Shangdong, China). Aloe extracts (AE, lyophilized powder, FBE013) were purchased from Five Brothers Bioproducts (Haikou, Hainan, China). Poly(vinyl alcohol) (PVA, 341584 Aldrich) was purchased from Sigma‐Aldrich (Saint Louis, MO, USA). All the chemicals were received as it is and used without further purification. L929 mouse fibroblast cells (ATCC CCL‐ 1), human fibroblast cells (HFCs, ATCC CCL110), and *Staphylococcus aureus* (*S. aureus*, ATCC

9213) were purchased from the American‐Type Culture Collection (Manassas, VA, USA). *Escherichia coli* (*E. coli*, Trans5α) was purchased from Transgen Biotech (Beijing, China).
