Hydrogels, due to their excellent biochemical and mechnical property, have shown attractive advantages in the field of wound dressings. However, a comprehensive review of the functional hydrogel as a wound dressing is still lacking. This work first summarizes the skin wound healing process and relates evaluation parameters and then reviews the advanced functions of hydrogel dressings such as antimicrobial property, adhesion and hemostasis, anti-inflammatory and anti-oxidation, substance delivery, self-healing, stimulus response, conductivity, and the recently emerged wound monitoring feature, and the strategies adopted to achieve these functions are all classified and discussed. Furthermore, applications of hydrogel wound dressing for the treatment of different types of wounds such as incisional wound and the excisional wound are summarized. Chronic wounds are also mentioned, and the focus of attention on infected wounds, burn wounds, and diabetic wounds is discussed. Finally, the future directions of hydrogel wound dressings for wound healing are further proposed.

The healing of an adult skin wound is a complex process requiring the collaborative efforts of many different tissues and cell lineages. The behavior of each of the contributing cell types during the phases of proliferation, migration, matrix synthesis, and contraction, as well as the growth factor and matrix signals present at a wound site, are now roughly understood. Details of how these signals control wound cell activities are beginning to emerge, and studies of healing in embryos have begun to show how the normal adult repair process might be readjusted to make it less like patching up and more like regeneration.

Injectable self-healing hydrogel dressing with multifunctional properties including anti-infection, anti-oxidative and conductivity promoting wound healing process will be highly desired in wound healing application and its design is still a challenge. We developed a series of injectable conductive self-healed hydrogels based on quaternized chitosan-g-polyaniline (QCSP) and benzaldehyde group functionalized poly(ethylene glycol)-co-poly(glycerol sebacate) (PEGS-FA) as antibacterial, anti-oxidant and electroactive dressing for cutaneous wound healing. These hydrogels presented good self-healing, electroactivity, free radical scavenging capacity, antibacterial activity, adhesiveness, conductivity, swelling ratio, and biocompatibility. Interestingly, the hydrogel with an optimal crosslinker concentration of 1.5 wt% PEGS-FA showed excellent in vivo blood clotting capacity, and it significantly enhanced in vivo wound healing process in a full-thickness skin defect model than quaternized chitosan/PEGS-FA hydrogel and commercial dressing (Tegaderm™ film) by upregulating the gene expression of growth factors including VEGF, EGF and TGF-β and then promoting granulation tissue thickness and collagen deposition. Taken together, the antibacterial electroactive injectable hydrogel dressing prolonged the lifespan of dressing relying on self-healing ability and significantly promoted the in vivo wound healing process attributed to its multifunctional properties, meaning that they are excellent candidates for full-thickness skin wound healing.Copyright © 2017 Elsevier Ltd. All rights reserved.

The antibacterial carboxymethyl chitosan/ZnO nanocomposite hydrogels were successfully prepared via in situ formation of ZnO nanorods in the crosslinked carboxymethyl chitosan (CMCh) matrix, by treating the CMCh hydrogel matrix with zinc nitrate solution followed by the oxidation of zinc ions with alkaline solution. The resulting CMCh/ZnO hydrogels were characterized by using FTIR spectroscopy, X-ray diffractormetry and scanning electron microscopy (SEM). SEM micrographs revealed the formation of ZnO nanorods in the hydrogel matrix with the size ranging from 190nm to 600nm. The swelling behavior of the prepared nanocomposite hydrogels was also investigated in different pH solutions. The CMCh/ZnO nanocomposite hydrogel showed rather higher swelling behavior in different pH solutions in comparison with neat CMCh hydrogel. Furthermore, the antibacterial activity of CMCh/ZnO hydrogel was studied against Escherichia coli and Staphylococcus aureus by CFU assay. The results demonstrated an excellent antibacterial activity of the nanocomposite hydrogel. Therefore, the developed CMCh/ZnO nanocomposite hydrogel can be used effectively in biomedical field. Copyright © 2016 Elsevier B.V. All rights reserved.

以马铃薯淀粉、羧甲基纤维素钠为成膜基材，紫薯花青素作为指示剂制备指示膜。研究马铃薯淀粉和羧甲基纤维素钠的比例、花青素质量分数、甘油质量分数对指示膜性能抗拉伸强度、断裂伸长率、水溶性、颜色（a值）的影响，将指示膜性能综合分作为响应值，采用响应面法优化制备工艺参数，并对最优指示膜进行表征。结果表明，当马铃薯淀粉和羧甲基纤维素钠质量比6∶4、花青素质量分数0.5%、甘油质量分数0.6%时，指示膜的综合分为63.8，此时对应的抗拉伸强度为（21.48±0.12）MPa，断裂伸长率为（28.88±0.08）%，水溶性为（19.24±0.21）%，a值为4.95±0.02。通过傅里叶变换红外光谱分析、X射线衍射和扫描电镜分析各组分之间相容性好，截面平整光滑。将指示膜用于监测草鱼新鲜度，鱼肉的挥发性盐基氮值、pH值以及菌落总数分别达到21.55 mg/100 g、7.58、7.3（lg（CFU/g））时，指示膜由红色变为蓝紫色。研究结果可为指示膜用于食品货架期指示应用提供参考。

Indicator films were prepared through using starch (S) and sodium carboxymethyl cellulose (CMC-Na) as the film forming material and purple sweet potato anthocyanins (PA) as the indicator. The effects of S/CMC-Na ratio, anthocyanin concentration and glycerol concentration on the tensile strength (TS), elongation at break (EAB), water solubility and color (a value) of films were investigated. Using the comprehensive score of indicator film performance was as the response value, the process parameters were optimized by the response surface methodology, and the optimal indicator film was characterized. The results demonstrated that the optimum formulation of indicator films was determined as follows: starch/CMC-Na ratio 6:4, anthocyanin concentration 0.5%, and glycerol concentration 0.6%. The overall score of the indicator film prepared using the optimized formulation were the highest, up to 63.8, and it showed tensile strength of (21.48 ± 0.12) MPa, elongation at break of (28.88 ± 0.08)%, water solubility of (19.24 ± 0.21)%, and a value of 4.95 ± 0.02. The results of Fourier-transform infrared (FT-IR) spectroscopy, X-ray-differentiation (XRD) and scanning electron microscopy (SEM) indicated that the cross section of the SCA film was smooth and showed a good compatibility among the ingredients. Furthermore, the indicator film was used to monitor the freshness of grass carp. When the total volatile basic nitrogen (TVB-N) value, pH and total viable count reached 21.55 mg/100 g, 7.58 and 7.3 (lg(CFU/g)), respectively, the indicator film changed from red to blue-violet. These research results provide a basis for the application of indicator films for food shelf life evaluation.

Wound dressings that can be formed in situ offer several advantages over the use of preformed dressings such as conformability without wrinkling or fluting in the wound bed, ease of application and improved patient compliance and comfort. Here we describe such an in situ forming hydrogel wound dressing from gelatin, oxidized alginate and borax. Periodate oxidized alginate rapidly cross-links proteins such as gelatin in the presence of borax to give in situ forming hydrogels that are both non-toxic and biodegradable. The composite matrix has the haemostatic effect of gelatin, the wound healing-promoting feature of alginate and the antiseptic property of borax to make it a potential wound dressing material. The hydrogel was found to have a fluid uptake of 90% of its weight which would prevent the wound bed from accumulation of exudates. The water vapour transmission rate (WVTR) of the hydrogel was found to be 2686+/-124 g/m2/day indicating that the hydrogel can maintain a moist environment over wound bed in moderate to heavily exuding wound which would enhance epithelial cell migration during the healing process. The wound healing efficacy of hydrogel was evaluated in experimental full thickness wounds using a rat model which demonstrated that within 2 weeks, the wound covered with gel was completely filled with new epithelium without any significant adverse reactions. These in situ forming hydrogels fulfil many critical elements desirable in a wound dressing material.

\n In this work, the varying color discrimination thresholds of human vision for textiles with a wide range of physical color attributes under different illumination conditions were examined. It was found that, regardless of the illumination condition and the color attributes of the textiles, people cannot generally perceive the color differences of textiles smaller than 4.25 Δ E*\n ab\n. Meanwhile, the color discrimination threshold was found to be significantly affected by the illuminance of illuminants and all the physical color attributes of lightness, chroma, and hue of the textiles observed. People were generally better able to distinguish color differences in bright environments with the illuminance of 2000 lux than in darker ones with 100 lux. In addition, color differences between dark and less-saturated textiles were found to be generally easier to be perceived than those between light and saturated textiles under various illuminants. In addition, regardless of the illuminant, color differences between neutral colored textiles were easier to be perceived than those between chromatic colored textiles with the mean color discrimination threshold of 2.85 and 4.42 Δ E*\n ab\n, respectively. In particular, among chromatic colored textiles, color differences between yellow textiles were generally the hardest to be perceived with the mean threshold of 5.58 Δ E*\n ab\n.\n