In vitro and in vivo evaluation of new PRP antibacterial moisturizing dressings for infectious wound repair

In this study, a solution chitosan fibroin emulsion with added Silver Nanoparticles (AgNPs) was freeze-dried to be the scaffold, and an asymmetric coating was formed on one side. PRP was loaded onto the composite scaffold using a secondary lyophilization technology to prepare the tissue engineering dressings. AgNPs were characterized using a transmission electron microscope. The morphologies of the composite dressing were examined under a scanning electron microscope. The silver content of the dressing was measured by inductively coupled plasma mass spectrometry. The asymmetric wettability of the composite dressing was demonstrated by water contact angle measurement. Relatively high porosity, favourable moisture retention capability and appropriate tensile strength were observed by measuring the physical and mechanical properties. Satisfactory antibacterial properties against various bacteria and microbial isolation performance were observed by the antibacterial effect analysis in vitro. The total protein slow-release property was measured using the BCA assay. Good biocompatibility and lower sensitization were examined both in vitro and in vivo. In addition, the healing effciency of the composite dressing on infected wound were examined in mice infected wound models. Analysis of wound healing rates, bacterial cultures of wound exudate, whole blood cell analysis and histological examination all showed satisfactory results. These results are demonstrated to provide a potential and possible pathway to promote wound tissue repair and regeneration.     

Influence of the stiffness of three-dimensional alginate/collagen-I interpenetrating networks on fibroblast biology

Wound dressing biomaterials are increasingly being designed to incorporate bioactive molecules to promote healing, but the impact of matrix mechanical properties on the biology of resident cells orchestrating skin repair and regeneration remains to be fully understood. This study investigated whether tuning the stiffness of a model wound dressing biomaterial could control the behavior of dermal fibroblasts. Fully interpenetrating networks (IPNs) of collagen-I and alginate were fabricated to enable gel stiffness to be tuned independently of gel architecture, polymer concentration or adhesion ligand density. Three-dimensional cultures of dermal fibroblasts encapsulated within matrices of different stiffness were shown to promote dramatically different cell morphologies, and enhanced stiffness resulted in upregulation of key-mediators of inflammation such as IL-10 and COX-2. These findings suggest that simply modulating the matrix mechanical properties of a given wound dressing biomaterial deposited at the wound site could regulate the progression of wound healing.     

Water absorbing and antibacterial properties of N-isopropyl acrylamide grafted and collagen/chitosan immobilized polypropylene nonwoven fabric and its application on wound healing enhancement

A durable sandwich wound dressing system with high liquid absorbing, biocompatibility, and antibacterial properties was designed. Various solution weight ratios of collagen to chitosan were used to immobilize on the polypropylene nonwoven fabric, which were pregrafted with acrylic acid (AA) or N-isopropyl acrylamide (NIPAAm) to construct a durable sandwich wound dressing membrane with high water absorbing, easy removal, and antibacterial activity. Swelling properties and antibacterial activity of the membranes were measured, and wound healing enhancement by skin full-thickness excision on animal model was examined. The results indicated that NIPAAm-grafted and collagen/chitosan-immobilized polypropylene nonwoven fabric (PP-NIPAAm-collagen-chitosan) showed a better healing effect than AA-grafted and collagen/chitosan-immobilized polypropylene nonwoven fabric (PP-AA-collagen-chitosan). The wound treated with PP-NIPAAm-collagen-chitosan demonstrated the excellent remodeling effect in histological examination with respect to the construction of vein, epidermis, and dermis at 21 days after skin injury. The values of water uptake and water diffusion coefficient for PP-NIPAAm-collagen-chitosan were higher than that for PP-AA-collagen-chitosan under a given solution weight ratio of collagen/chitosan. Both PP-NIPAAm-collagen-chitosan and PP-AA-collagen-chitosan demonstrated antibacterial activity.     

Dual growth factor releasing multi-functional nanofibers for wound healing

The objective of this research is to develop a dual growth factor-releasing nanoparticle-in-nanofiber system for wound healing applications. In order to mimic and promote the natural healing procedure, chitosan and poly(ethylene oxide) were electrospun into nanofibrous meshes as mimics of extracellular matrix. Vascular endothelial growth factor (VEGF) was loaded within nanofibers to promote angiogenesis in the short term. In addition, platelet-derived growth factor-BB (PDGF-BB) encapsulated poly(lactic-co-glycolic acid) nanoparticles were embedded inside nanofibers to generate a sustained release of PDGF-BB for accelerated tissue regeneration and remodeling. In vitro studies revealed that our nanofibrous composites delivered VEGF quickly and PDGF-BB in a relayed manner, supported fibroblast growth and exhibited anti-bacterial activities. A preliminary in vivo study performed on normal full thickness rat skin wound models demonstrated that nanofiber/nanoparticle scaffolds significantly accelerated the wound healing process by promoting angiogenesis, increasing re-epithelialization and controlling granulation tissue formation. For later stages of healing, evidence also showed quicker collagen deposition and earlier remodeling of the injured site to achieve a faster full regeneration of skin compared to the commercial Hydrofera Blue® wound dressing. These results suggest that our nanoparticle-in-nanofiber system could provide a promising treatment for normal and chronic wound healing.     

Egg white/poly (vinyl alcohol)/MMT nanocomposite hydrogels for wound dressing

Nanocomposite hydrogels on the basis of egg white and poly (vinyl alcohol) (PVA) containing 0, 5, and 10 wt.% of montmorillonite (MMT) nanoclay were prepared by a facile cyclic freezing–thawing technique and their properties investigated for wound dressing application. The morphological, structural, thermal, physical, and in vitro cytotoxic properties of the prepared nanocomposite hydrogel wound dressings (NHWDs) were experimentally studied. The NHWDs had an exfoliated morphology with a porous structure having pores sizes in the nanometric scale. It was shown that MMT acted as cross-linker in the network of NHWDs and improved their thermal stabilities. The prepared wound dressings were transparent and their equilibrium water contents and water vapor transmission rates, as two important factors of wound dressings, were very close to the properties of human skin which means that the prepared wound dressings could interact appropriately with the damaged tissues of wounds and protect them like an artificial skin during the wound healing process. The in vitro cytotoxicity assay also confirmed the non-cytotoxic nature of the prepared NHWDs. It was finally concluded that the prepared egg white/PVA/MMT nanocomposite hydrogels are promising materials to be used as novel wound dressings in wound and burn care.     

肉芽组织下注射微粒皮浆对大鼠创伤性慢性创面愈合的影响

目的研究肉芽组织下注射微粒皮浆对大鼠创伤性慢性创面愈合的作用。 方法选取60只SD雄性大鼠,于背部制作大小为3.0 cm×3.0 cm的创面,并将钢丝圈缝于创面内缘。按照随机数字表法将大鼠分为3组,分别为一般创面组、慢性创面组和微粒皮浆组,每组各20只。一般创面组背部造成创面后给予抗感染治疗并常规换药;慢性创面组背部形成创面后给予抗感染治疗、常规换药,并连续7 d肌内注射氢化可的松干预形成慢性创面;微粒皮浆组背部形成创面后给予抗感染治疗、常规换药,连续7 d肌内注射氢化可的松干预形成慢性创面,取大鼠右大腿外侧皮肤制备微粒皮浆注射于肉芽组织下。造模完成次日开始观察创面情况,定为观察第1天。观察第7、14、21、28天各组创面愈合情况,并计算创面愈合率;留取观察第14天的肉芽组织进行苏木精-伊红染色以及CD31免疫组织化学染色,观察苏木精-伊红染色下创面新生毛细血管分布情况及CD31免疫组织化学染色下CD31表达情况与微血管密度。对数据行单因素方差分析和LSD-t检验。 结果观察第14天,一般创面组创面明显缩小,慢性创面组皮肤爬伸不明显,微粒皮浆组创面大部分愈合;观察第28天,一般创面组剩余部分残留创面,慢性创面组创面愈合不明显,微粒皮浆组创面基本愈合。观察第14、21、28天,一般创面组愈合率分别为(51.09±0.94)%、(75.43±0.92)%、(86.51±0.57)%,慢性创面组创面愈合率分别为(20.30±0.95)%、(35.59±1.18)%、(45.82±1.35)%,微粒皮浆组创面愈合率分别为(39.00±0.86)%、(64.62±0.15)%、(91.25±0.87)%,比较差异均有统计学意义(F＝1 993.60、6 475.02、9 984.47,P值均小于0.05);观察第14天,慢性创面组创面愈合率分别与一般创面组、微粒皮浆组比较,差异均有统计学意义(t＝89.90、50.93,P值均小于0.05);观察第21天,慢性创面组创面愈合率分别与一般创面组、微粒皮浆组比较,差异均有统计学意义(t＝117.90、116.10,P值均小于0.05);观察第28天,慢性创面组创面愈合率分别与一般创面组、微粒皮浆组比较,差异均有统计学意义(t＝86.43、94.29,P值均小于0.05)。观察第14天,创面苏木精-伊红染色观察,一般创面组可见少许新生毛细血管,慢性创面组未见明显新生毛细血管,微粒皮浆组其间有大量新生毛细血管。观察第14天,创面CD31免疫组织化学染色观察(CD31阳性表达呈棕黄色),一般创面组棕黄色的颗粒散在分布,慢性创面组棕黄色颗粒稀疏分布,微粒皮浆组可见大量棕黄色的颗粒分布。观察第14天,创面微血管密度比较,一般创面组、慢性创面组、微粒皮浆组微血管密度分别为(49.20±17.96)、(37.32±9.57)、(64.93±20.29)个/视野,比较差异有统计学意义(F＝34.09,P<0.05);慢性创面组创面微血管密度分别与一般创面组、微粒皮浆组比较,差异有统计学意义(t＝3.23、11.50,P值均小于0.05)。 结论微粒皮浆肉芽组织下注射可促进大鼠创伤性慢性创面血管增生,其创面愈合率明显升高,创面愈合时间缩短。     

创面复合液体敷料在皮肤创伤中的治疗研究

基于羧甲基壳聚糖的高生物相容性及聚乙烯醇缩丁醛的快速成膜,构建了一种创面复合液体敷料,并对其应用效果进行评价。首先应用羧甲基壳聚糖 (CMC)、聚乙烯醇缩丁醛 (PVB)和乙醇溶液,按照一定的比例,制备创面复合液体敷料。对其防水、透气、阻菌、细胞毒性进行性能研究及安全性评价。然后选择健康成年Sprague-Dawley(SD)大鼠40只,雌雄各半,构建大鼠创面模型,并将含有不同浓度的羧甲基壳聚糖(1.0、10.0、30.0 mg/mL)应用在其创面上,通过日常观察、HE染色等,研究创面复合液体敷料在皮肤创伤中的治疗效果。结果显示创面复合液体敷料上层膜液在1.8～2.3 mm 之间具有很好的防水透气性、阻菌性及生物兼容性。运用在动物模型上可以看到,第7 d含有10.0、30.0 mg/mL CMC组的大鼠创面愈合率分别为65.42%、67.38%,明显高于对照组且存在显著性差异(P< 0.01),14 d后含有10.0、30.0 mg/mL CMC组的大鼠创面愈合率已达到100%。HE 染色的第七天含有10.0、30.0 mg/mL CMC的创面复合液体敷料组中观察到有复层扁平的表皮和真皮的胶原纤维,第12 d组织开始出现内陷结构,含有厚实、粗糙胶原纤维的正常真皮与较薄的胶原纤维水平连接,表皮的复层鳞状上皮远远大于对照组中的三到四层。而且创面连接真皮结缔组织,它的表皮构成非常接近于正常皮肤组织。构建的创面复合液体敷料(10.0 mg/mL CMC)具备良好的防水、透气、阻菌性以及生物兼容性,随着羧甲基壳聚糖浓度的升高,治疗急性创面的效果越好,创面复合液体敷料能够对创面起到早期保护和促进愈合的效果。.     

生物敷料A对比银离子水胶体油纱修复面部Ⅱ度烧伤

背景：在临床治疗面部Ⅱ度烧伤中,生物敷料A及银离子水胶体油纱在吸收渗液、黏附性、抗菌等方面都具有不错的表现。 目的：观察面部Ⅱ度烧伤早期清创后生物敷料A对比银离子水胶体油纱覆盖的临床疗效。 方法：纳入15例浅Ⅱ度及10例深Ⅱ度面部烧伤患者,将同一患者相同烧伤深度及同等大小的对称创面分两侧治疗,实验侧清创后采用生物敷料A覆盖创面,对照侧清创后采用银离子水胶体油纱覆盖创面,对比两侧创面愈合时间、创面感染情况、换药次数、创面愈合后皮肤质量情况、换药舒适度及敷料覆盖舒适度。 结果与结论：在浅Ⅱ度烧伤患者中,实验侧换药次数及敷料覆盖舒适度优于对照侧(P < 0.05),换药舒适度差于对照侧(P < 0.05),两侧创面愈合时间、创面感染及愈合后皮肤质量情况无差异。在深Ⅱ度烧伤患者中,实验侧创面愈合时间、换药次数、愈合后皮肤质量情况、换药舒适度及敷料覆盖舒适度优于对照侧(P < 0.05),换药舒适度差于对照侧(P < 0.05),两侧创面感染情况无差异。表明生物敷料A与银离子水胶体油纱修复面部浅Ⅱ度烧伤创面的疗效相似,但生物敷料A修复深Ⅱ度烧伤创面更有利于促进创面愈合,提高创面愈合质量。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

护创膜对兔创面愈合的影响

目的探讨护创膜对兔创面愈合的影响。方法制做兔背全层创伤模型,分成实验组和对照组,创面分别外用护创膜及无菌凡士林敷料。伤后3、5、7、10、l4、17、21d观察两组创面愈合时间和创面愈合率;并分别取创面组织进行病理组织学检查评估创面的修复质量,对实验组和对照组的创面愈合时间和创面愈合率及修复质量进行观察比较。结果护创膜与凡士林纱布相比能加速创面愈合(P<0.O5),护创膜组在皮肤愈合的组织病理等级评分上优于凡士林纱布组(P<0.05)。结论护创膜促进创面愈合并提高愈合的质量,是创面修复的一种较理想的生物敷料。     

体外培养表皮干细胞复合高分子支架原位修复深度烧伤创面的研究

目的探讨表皮干细胞联合成纤维细胞-丝素蛋白纳米纤维活性支架体内培养,对Ⅲ度烧伤创面的修复和再生作用。方法（1）表皮干细胞的培养和表征：采用快速贴壁法分离和培养表皮干细胞（Epidermal Stem Cell,ESC）。将表皮干细胞分别在经Ⅳ型胶原蛋白修饰的和未经修饰的培养瓶中,或通过悬浮法培养,研究表皮干细胞的生长特性;以β1整合素和细胞角蛋白CK19免疫荧光染色实验考察细胞表型。（2）活性支架的体外构建和对大鼠Ⅲ度创面的修复作用研究：体外构建成纤维细胞-丝素蛋白纳米纤维活性支架;采取同体对照法,在20只Sprague—Dawley大鼠（sD大鼠）背部制作两个Ⅲ度切痂创面。左侧创面采用体外培养的自体表皮干细胞联合成纤维细胞一丝素蛋白纳米纤维活性支架移植入创面,作为组织工程移植物组;右侧创面采用凡士林纱布敷料覆盖,作为凡士林纱布敷料组。考察组织工程移植物对大鼠Ⅲ度创面的愈合作用。结果以快速贴壁法能够有效地分离得到表皮干细胞,细胞在经Ⅳ型胶原蛋白修饰的培养瓶中生长10d后融合,数目达到5．1×10^5／cm^2。免疫荧光实验表明细胞表面抗原呈β1整合素和角蛋白免疫CK19成阳性,证明分离得到的细胞为表皮干细胞。成纤维细胞能够在丝素蛋白纳米纤维中扩增并分泌细胞外基质,14d后与丝素蛋白纳米纤维形成活性支架。对大鼠Ⅲ度烧伤创面的修复实验表明,组织工程移植物组的创面在第14天和第22天的平均愈合效率为66％和93％,高于凡士林纱布敷料组（32％和69％）,P〈0．05。组织工程移植物组的创面平均愈合天数为21d,低于凡士林纱布敷料组（31d）,P〈0．05。结论通过Ⅳ型胶原蛋白黏附法,能够分离得到表皮干细胞,并且其在Ⅳ型胶原蛋白表面修饰的培养瓶中的生长活力较高。大鼠Ⅲ度创面的修复实验表明,组织工程移植物,即表皮干细胞联合成纤维细胞-丝素蛋白纳米纤维支架,能够修复Ⅲ度创面,再生皮肤表真皮结构完整;并且与凡士林纱布敷料相比,能够提高创面的愈合效率,减少创面的愈合时间。     

组织工程活性皮肤用于皮肤慢性溃疡创面临床研究

目的探讨组织工程活性皮肤修复皮肤慢性溃疡创面临床应用的有效性及安全性。方法选取不同临床单位符合临床试验要求的皮肤溃疡患者，随机分为试验组和对照组，试验组应用组织工程活性皮肤覆盖创面，对照组应用常规凡士林纱布覆盖，所有患者采用常规包扎并固定。临床研究观察时间为6个月，观察指标为治疗期患者的创面变化、创面愈合时间和愈合后的创面愈合质量；同时对全身及重要脏器进行检测。采用SPSS统计软件对试验组和对照组平均愈合时间进行t检验，分析两组间差异有无统计学意义。结果应用组织工程活性皮肤可在创面存活，促进创缘皮肤组织的新生并替代组织工程活性皮肤。与对照组相比应用后创面明显缩小，试验组的平均愈合时间24，37d，明显少于对照组（64．05d），有统计学意义。结论应用组织工程活性皮肤修复慢性皮肤溃疡创面可促进创面早期修复、缩短病程并降低由此产生的并发症；为组织工程活性皮肤的临床应用提供了切实可行的方法。     

湿性敷料治疗皮肤Ⅱ度烧伤的比较

背景：已有基础实验证明,伤口在湿性环境下的愈合效果优于干性环境,湿性敷料的研究是皮肤创面愈合研究的重点。 目的：观察湿性敷料对皮肤Ⅱ度烧伤创面的治疗效果。 方法：选取在海南省人民医院门诊接受治疗的38例Ⅱ度烧伤患者,采用自身对照法将创面分为治疗组和对照组,治疗组采用湿性敷料覆盖治疗烧伤创面,对照组采用碘伏纱布或凡士林纱布覆盖,治疗后分别观察两种不同处理方法对创面的愈合效果及对疼痛程度的影响。 结果与结论：所有患者均纳入结果分析,治疗组患者烧伤创面的平均愈合时间为(9.8±3.1) d,对照组创面平均愈合时间为(13.1±2.2) d,两者比较差异有显著性意义(P < 0.01)。治疗组创面疼痛程度明显低于对照组(P < 0.01)。使用湿性敷料(美皮贴或美皮康)治疗Ⅱ度烧伤,可以使创面愈合时间缩短,创面疼痛程度明显降低。     

Development of a Wound Dressing Composed of Hyaluronic Acid Sponge Containing Arginine and Epidermal Growth Factor

Hyaluronic acid (HA) has the ability to promote wound healing. Epidermal growth factor (EGF) is able to promote the proliferation of various cell types, in addition to epidermal cells. A novel wound dressing was designed using high-molecular-weight hyaluronic acid (HMW-HA) and low-molecular-weight hyaluronic acid (LMW-HA). Spongy sheets composed of cross-linked high-molecular-weight hyaluronic acid (c-HMW-HA) were prepared by freeze-drying an aqueous solution of HMW-HA containing a crosslinking agent. Each spongy sheet was immersed into an aqueous solution of LMW-HA containing arginine (Arg) alone or both Arg and epidermal growth factor (EGF), and were then freeze-dried to prepare two types of product. One was a wound dressing composed of c-HMW-HA sponge containing LMW-HA and Arg (c-HMW-HA/LMW-HA + Arg; Group I). The other was a wound dressing composed of c-HMW-HA sponge containing LMW-HA, Arg and EGF (c-HMW-HA/LMW-HA + Arg + EGF; Group II). The efficacy of these products was evaluated in animal tests using rats. In the first experiment, each wound dressing was applied to a full-thickness skin defect with a diameter of 35 mm in the abdominal region of Sprague–Dawley (SD) rats, leaving an intact skin island measuring 15 mm in diameter in the central area of this skin defect. Commercially available polyurethane film dressing was then applied to each wound dressing as a covering material. In the control group, the wound surface was covered with polyurethane film dressing alone. Both wound dressings (Group I and Group II) potently decreased the size of the full-thickness skin defect and increased the size of the intact skin island, when compared with the control group. The wound dressing in Group II showed particularly potent activity in increasing the distance of epithelization from the intact skin island. This suggests that EGF release from the spongy sheet serves to promote epithelization. The wound dressing in Group II enhanced early-stage inflammation after 1 week, as compared with the other two groups. In the second experiment, each wound dressing was applied to a full-thickness skin defect measuring 35 mm in diameter in the abdominal region of SD rats, after removing necrotic skin caused by dermal burns. Polyurethane film dressing was applied to each wound dressing as a covering material. In the control group, the wound surface was covered with polyurethane film dressing alone. Both wound dressings (Group I and Group II) potently decreased the size of the full-thickness skin defect and increased epithelization from the wound margin, as compared with the control group. The wound dressing in Group II was found to enhance early-stage inflammation after 1 week, as compared with the other two groups. The findings in both experiments indicate that the wound dressing composed of HA-based spongy sheets containing Arg and EGF potently promotes wound healing by inducing moderate inflammation. The release of EGF in the early stages of wound healing induces moderate inflammation. This suggests that wound healing is facilitated directly by topical application of EGF, and indirectly by cytokines derived from inflammatory cells stimulated by EGF.     

Spandra: a sustained release battlefield wound dressing

In 1981, our laboratories developed a family of elastomers which could be cured by ultraviolet (UV) radiation. Curing by UV radiation was a significant advance in chemistry, since it allowed ultra-fast curing of elastomers in a matter of seconds, as compared to several hours at 110 degrees C for conventional heat curing. We applied for a patent based on this technology, and the patent was allowed in mid-1984 [29]. Based on this technology, Thermedics submitted a proposal to the US Army for the development of a sustained-release battlefield wound dressing containing antibiotics and coagulants. The drugs were evenly distributed in the oligomer matrix, and subsequently cured in seconds under UV illumination, without the use of heat, organic solvents or water. Because delicate drugs are not subjected to heat, organic solvents or water, the pharmacological activity of the drugs is insured. Therefore, theoretically any drug may be incorporated into our dressing. Sustained release dressings were first developed at Thermedics in 1983, spurred by a contract from the US Army Medical Research and Development Command. Under this contract, the Company developed a new type of wound dressing capable of accelerating the healing process, retarding infection, and minimizing pain. Based on our TECOFLEX materials technology, the dressing performs like temporary artificial skin. Its transmission properties for oxygen, carbon dioxide, and water vapor are similar to those of intact skin. Thus, while excluding bacteria from the wound site, the dressing maintains an optimal moist environment for the promotion of rapid healing. The new drawing shown in Figure 10 minimizes pain during healing by preventing dehydration and shrinkage in the wound. Patient comfort is also enhanced by the incorporation of a special fabric which imparts flex properties to the bandage that are almost identical to those of human skin, with greater stretch in one direction than in another. This also facilitates application to complex body contours by only one attendant, an important feature in both hospital and emergency situations. Materials currently in use in hospitals are difficult to handle, requiring two or three nurses to apply large dressings. Thermedics' military wound dressing not only has the significant advantage of ease of application, but this dressing can also be used for delivery of drugs to a specific site.(ABSTRACT TRUNCATED AT 400 WORDS)     

三种创面敷料在薄中厚皮片供皮区的应用研究

目的观察3种创面敷料对薄中厚皮片供皮区创面愈合的影响。 方法选取蚌埠医学院第一附属医院整形烧伤科2020年1月至12月收治的38例自体皮片移植术患者。在同一患者供皮区分别取相同面积的类矩形薄中厚皮片3处,每处均间隔1 cm,每例所取皮片总面积基本相同,将同一患者的3处供皮区分为凡士林敷料组、银离子藻酸盐敷料组和丝素蛋白膜状敷料组3组,取皮后分别贴敷凡士林敷料、银离子藻酸盐敷料和丝素蛋白膜状敷料。对比3组供皮区创面积血率、初次换药时患者的疼痛程度[数字评定量表(NRS)]、创面感染率、创面上皮化愈合时间、创面后期愈合效果。对数据行单因素方差分析、t检验和χ²检验。 结果(1)创面积血率：丝素蛋白膜状敷料组创面积血率(23.68%)分别高于分别高于凡士林敷料组(2.63%)和银离子藻酸盐敷料组(5.26%),差异均有统计学意义(χ²＝ 7.370、5.208, P<0.05),凡士林敷料组与银离子藻酸盐敷料组积血率比较,差异无统计学意义(χ²＝0.347, P>0.05);(2)初次换药时疼痛程度评价：丝素蛋白膜状敷料组的NRS评分为(2.97±1.48)分,分别低于银离子藻酸盐敷料组[(3.97±1.84)分]和凡士林敷料组[(6.03±1.37)分],差异均有统计学意义(t＝ 4.854、0.873, P<0.05);银离子藻酸盐敷料组疼痛评分低于凡士林敷料组,差异有统计学意义(t＝1.467, P<0.05);(3)创面感染率：银离子藻酸盐敷料组创面感染率(5.26%)分别与丝素蛋白膜状敷料组(0)和凡士林敷料组(10.53%)比较,差异均无统计学意义(χ²＝ 2.054、0.724, P>0.05);丝素蛋白膜状敷料组与凡士林敷料组比较,感染率低,差异有统计学意义(χ²＝ 4.222, P<0.05);(4)创面上皮化愈合时间：丝素蛋白膜状敷料组创面上皮化愈合时间为(8.95±1.34) d,与银离子藻酸盐敷料组[(13.69±1.64) d]以及凡士林敷料组[(11.78±1.43) d]比较,愈合时间均较短,差异均有统计学意义(t＝0.953、1.204, P<0.05)。与银离子藻酸盐敷料组比较,凡士林敷料组愈合时间短,差异有统计学意义(t＝2.147, P<0.05);(5)创面后期愈合效果：3组在瘢痕增生和色素沉着2方面均无明显差异。 结论丝素蛋白膜状敷料应用于薄中厚皮片供皮区,具有相对无痛、抗感染能力强、上皮化愈合时间短等优势,但在防止创面积血方面效果欠佳。     

Morphofunctional evaluation of the effect of collagen-1-based dressing on skin regeneration after burn trauma in mice of two genetic strains

Morphofunctional evaluation of the effect of biological dressing with collagen-1 on healing of 3A degree burn wound in outbred and mutant Hr ^hrHr^hr (hairless) mice was carried out by the histological method and optic radioautography. A pronounced stimulatory effect of the dressing on skin regeneration in mice was demonstrated. According to radioautography data, early dressing of the burn wounds in Hr ^{hr hr}mice led to active proliferation of epithelial cells in dermal cyst and vascular endotheliocytes. The possible mechanisms of the stimulatory effect of collagen-based dressing on wound healing are discussed.     

Investigation of lysine acrylate containing poly(N-isopropylacrylamide) hydrogels as wound dressings in normal and infected wounds

The design of materials for cutaneous wound dressings has advanced from passive wound covers to bioactive materials that promote skin regeneration and prevent infection. Crosslinked poly(N-isopropylacrylamide) (PNIPAAm)-based hydrogels have been investigated for a number of biomedical applications. While these materials can be used for drug delivery, limited cell interactions restrict their biological activity. In this article, acryoyl-lysine (A-Lys) was incorporated into poly(ethylene glycol) crosslinked PNIPAAm to enhance biological activity. A-Lys could be incorporated into the hydrogels to improve cellular interaction in vitro, while maintaining swelling properties and thermoresponsive behavior. Polyhexamethylene biguanide, an antimicrobial agent, could be encapsulated and released from the hydrogels and resulted in decreased bacteria counts within 2 hours. Two in vivo animal wound models were used to evaluate the hydrogel wound dressing. First, application of the hydrogels to a rodent cutaneous wound healing model resulted in significant increase in healing rate when compared with controls. Moreover, the hydrogels were also able to decrease bacteria levels in an infected wound model. These results suggest that PNIPAAm hydrogels containing A-Lys are promising wound dressings due to their ability to promote healing and deliver active antimicrobial drugs to inhibit infection.     

藻酸盐银联合水凝胶敷料对慢性创面愈合的作用

背景：研究发现藻酸盐及水凝胶敷料等均可促进创面愈合,而新型敷料藻酸盐银联合水凝胶敷料,对于难治慢性创面的愈合作用尚不清楚。 目的：观察藻酸盐银联合水凝胶敷料对慢性创面治疗的作用。 方法：选择江苏省人民医院烧伤整形科住院慢性创面患者34例,随机分为2组：治疗组应用藻酸盐银联合水凝胶敷料序贯换药;对照组采用1%磺胺嘧啶银冷霜抹在凡士林纱布上外敷,于治疗后7,10,14,17,21 d进行创面分泌物细菌培养、观察创面愈合情况及速度、药物不良反应、换药时创面痛感、肉芽破坏等情况。 结果与结论：治疗组创面细菌检出率明显低于对照组(P < 0.05)。治疗组创面愈合时间比对照组平均缩短约6 d,创面愈合速度较对照组明显加快(P < 0.05)。两组均无药物不良反应,治疗组创面换药时无明显疼痛感,肉芽组织无明显破坏。提示藻酸盐银联合水凝胶敷料序贯治疗慢性创面具有显著抗菌及促进创面肉芽组织和上皮再生、促进创面愈合的作用,且无不良反应。     

Control of wound infections using a bilayer chitosan wound dressing with sustainable antibiotic delivery.

A novel bilayer chitosan membrane was prepared by a combined wet/dry phase inversion method and evaluated as a wound dressing. This new type of bilayer chitosan wound dressing, consisting of a dense upper layer (skin layer) and a sponge-like lower layer (sublayer), is very suitable for use as a topical delivery of silver sulfadiazine (AgSD) for the control of wound infections. Physical characterization of the bilayer wound dressing showed that it has excellent oxygen permeability, that it controls the water vapor transmission rate, and that it promotes water uptake capability. AgSD dissolved from bilayer chitosan dressings to release silver and sulfadiazine. The release of sulfadiazine from the bilayer chitosan dressing displayed a burst release on the first day and then tapered off to a much slower release. However, the release of silver from the bilayer chitosan dressing displayed a slow release profile with a sustained increase of silver concentration. The cultures of Pseudomonas aeruginosa and Staphylococcus aureus in agar plates showed effective antimicrobial activity for 1 week. In vivo antibacterial tests confirmed that this wound dressing is effective for long-term inhibition of the growth of Pseudomonas aeruginosa and Staphylococcus aureus at an infected wound site. The results in this study indicate that the AgSD-incorporated bilayer chitosan wound dressing may be a material with potential antibacterial capability for the treatment of infected wounds.