Photocrosslinkable chitosan as a dressing for wound occlusion and accelerator in healing process.

Application of ultraviolet light (UV-) irradiation to a photocrosslinkable chitosan (Az-CH-LA) aqueous solution resulted in an insoluble, flexible hydrogel like soft rubber within 60 s. The chitosan hydrogel could completely stop bleeding from a cut mouse tail within 30 s of UV-irradiation and could firmly adhere two pieces of sliced skins of mouse to each other. In order to evaluate its accelerating effect on wound healing, full thickness-skin incisions were made on the back of mice and subsequently an Az-CH-LA aqueous solution was added into the wound and irradiated with UV light for 90 s. Application of the chitosan hydrogel significantly induced wound contraction and accelerated wound closure and healing. Histological examinations also have demonstrated an advanced granulation tissue formation and epithelialization in the chitosan hydrogel treated wounds. The chitosan hydrogel due to its accelerating healing ability is considered to become an excellent dressing for wound occlusion and tissue adhesive in urgent hemostasis situations.     

Chitosan hydrogel as a drug delivery carrier to control angiogenesis

An aqueous solution of photocrosslinkable chitosan containing azide groups and lactose moieties (Az-CH-LA) incorporating paclitaxel formed an insoluble hydrogel within 30 s of ultraviolet light (UV) irradiation. The chitosan hydrogel showed strong potential for use as a new tissue adhesive in surgical applications and wound dressing. The fibroblast growth factor (FGF)-2 molecules retained in the chitosan hydrogel and in an injectable chitosan/IO₄-heparin hydrogel remain biologically active, and were gradually released from the hydrogels as they biodegraded in vivo. The controlled release of biologically active FGF-2 molecules from the hydrogels caused induction of angiogenesis and collateral circulation occurred in healing-impaired diabetic (db/db) mice and in the ischemic limbs of rats. Paclitaxel, which is an antitumor reagent, was also retained in the chitosan hydrogel and remained biologically active as it was released on degradation of the hydrogel in vivo. The chitosan hydrogels incorporating paclitaxel effectively inhibited tumor growth and angiogenesis in mice. The purpose of this review is to describe the effectiveness of chitosan hydrogel as a local drug delivery carrier for agents (e.g., FGF-2 and paclitaxel) to control angiogenesis. It is thus proposed that chitosan hydrogel may be a promising new local carrier for drugs such as FGF-2 and paclitaxel to control vascularization.     

组织工程生物绷带及敷料在创伤修复领域中的应用

背景：医用敷料作为伤口处的覆盖物,在伤口愈合过程中,可以替代受损的皮肤起到暂时性屏障作用,避免或控制伤口感染,提供有利于创面愈合的环境。如何既能快速固定、有效止血,又可以减轻或避免止血后对伤肢血循环造成的不利影响,加快伤口愈合、减轻伤痛是创伤急救医学亟待解决的难题。 目的：文章综述了医用生物敷料在创伤修复领域中的应用现状及研究进展,揭示其发展前景,为其在创伤修复过程中的应用提供理论基础。 方法：应用计算机检索CNKI和PubMed数据库中1998-01/2008-12关于医用生物敷料的文章,在标题和摘要中以“医用敷料;生物材料,壳聚糖,水凝胶,组织工程”或“medical dressing,chitosan”为检索词进行检索。选择文章内容与创伤修复相关,同一领域文献则选择近期发表或发表在权威杂志文章。初检得到146篇文献,中文107篇,英文39篇,根据纳入标准选择38篇文章进行综述。 结果与结论：就目前临床使用及研究的医用敷料,根据其所用的材料将其分成了天然材料和合成高分子,无机材料和复合材料,并对敷料类产品质量控制中出现的问题进行了讨论,展望了敷料类产品的未来发展方向。为医用敷料类产品的研发提供理论依据。     

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.     

综合法治疗慢性压力性创伤所致压疮的疗效观察

目的总结慢性压力性创伤所致压疮的外科治疗经验。方法1997年1月至2008年12月,郴州市第一人民医院烧伤整形科应用皮瓣、游离皮片、术后灌洗及负压吸引等外科方法治疗107例因截瘫、侧瘫、超高龄痴呆等原因导致慢性压力创伤性皮肤、软组织溃烂创面382处。其中尾骶区121处,股骨大转子区96处,坐骨结节63处,髂骨部48处,胸腰椎区22处,足跟部15处,肩胛区17处。围手术期营养不良患者予以营养代谢支持治疗,感染严重者术后持续灌洗与负压吸引,并防止再受压等。结果 382处创面一次性愈合304处,其中158处为肌瓣或肌皮瓣,轴型复合组织瓣76处,游离皮片54处,邻位皮瓣16处。延迟愈合78处,其中轴型复合组织瓣41处,肌皮瓣31处,游离皮片6处。延迟愈合创面修复方法：38处经Ⅱ期扩创后直接缝合治愈,27处经游离皮片移植治愈,13处局部换药治愈（平均17d）。随访6个月时,原位复发压力性创面17例,其中游离植皮占13例。结论改善全身营养,控制局部细菌感染,利用创面周围健康皮肤、肌肉、筋膜形成复合组织瓣修复创面,辅以创底灌洗、负压吸引,避免再受压等是提高慢性压力创伤性创面治愈率和降低复发率的较好方法。     

Evaluation of alginate dialdehyde cross-linked gelatin hydrogel as a biodegradable sealant for polyester vascular graft

Vascular grafts are devices intended to replace compromised arteries in the body and grafts made of polyethylene terephthalate (PET) fabric have been used mainly for synthetic grafting procedures involving medium to large diameter vascular grafts. Though porosity of the graft permits tissue in-growth, it would lead to bleeding through the graft walls immediately after implantation. So it is essential to seal the pores either by preclotting with patient's own blood or by other sealing materials prior to implantation in order to prevent blood leakage through the graft wall. Biodegradable hydrogel materials are ideal candidates for this purpose. Apart from sealing the pores, they offer biocompatible and low-thrombogenic surfaces when coated on vascular graft. In the present study, a biodegradable hydrogel, derived from oxidized alginate and gelatin, has been deposited on PET grafts by dip coating and were characterized for its efficacy on sealing the pores of the graft. Water permeability in the static and pulsatile conditions, burst strength, in vitro cell culture cytotoxicity, hemocompatibility, and endothelial cell adhesion and proliferation of the coated grafts were investigated. Results showed that the alginate dialdehyde cross-linked gelatin hydrogel was nontoxic, hemocompatible, and was efficient in sealing the pores of the graft. Blood perfusion study showed that when hydrogel-coated grafts were exposed to blood for 30 min, they showed little affinity toward platelets or leukocytes. Hemolytic potential of PET was significantly reduced when it was coated with hydrogel. Improved adhesion and proliferation of endothelial cells were observed when PET grafts were coated with hydrogel. Results also showed that coating with hydrogel did not affect the burst strength of the PET graft.     

羧甲基壳聚糖膜促进大鼠微粒皮移植创面愈合的实验研究

目的：本研究旨在评估羧甲基壳聚糖膜取代异体皮作为微粒皮移植载体促进创面愈合的作用。方法28只大鼠中,每次随机抽取2只大鼠配对同时手术,在大鼠背部两侧制作直径25 mm、对称圆形全层皮肤缺损创面各1个,两侧创面分别设为实验组和对照组,均移植自体微粒皮,对照组创面覆盖相互配对大鼠的异体皮,实验组创面覆盖羧甲基壳聚糖膜。于术后7、11、14 d 观察记录各组创面愈合时间,并于术后7、14、19 d 采集创面组织行组织病理学检查。结果实验组的羧甲基壳聚糖膜覆盖下微粒皮能够成活,且能修复创面。实验组创面平均愈合时间为（15.6±2.0）d,短于对照组创面平均愈合时间为（18.8±1.9）d,两组比较,差异有统计学意义（t =8.987,P〈0.05）。组织切片结果显示：羧甲基壳聚糖膜覆盖下微粒皮修复的新生表皮层生长较异体皮覆盖下新生表皮厚。结论羧甲基壳聚糖膜作为生物敷料,能够有效地保护创面,提供微粒皮修复创面的微环境。可用于取代异体皮覆盖微粒皮移植的创面。     

负压吸引术在四肢骨折伴严重软组织损伤中的应用

目的分析负压吸引术在四肢骨折伴严重软组织损伤患者的临床应用效果。方法将符合条件的83例患者分为观察组(n=42)和对照组(n=41)。观察组采用负压吸引术治疗,对照组采用常规换药治疗。比较2组植皮所需时间、住院时间、首次植皮存活率及创面细菌感染率。结果观察组患者植皮所需时间及住院时间均显著短于对照组,2组比较差异有统计学意义(P0.05);观察组首次植皮存活率显著高于对照组(P0.05),创面细菌感染率显著低于对照组(P0.01)。结论负压吸引术对于四肢骨折伴严重软组织损伤患者临床疗效优于传统换药法,值得临床推广应用。     

Photocrosslinkable chitosan hydrogel containing fibroblast growth factor-2 stimulates wound healing in healing-impaired db/db mice

Application of ultraviolet light (UV-) irradiation to a photocrosslinkable chitosan (Az-CH-LA) aqueous solution including fibroblast growth factor-2 (FGF-2) resulted within 30s in an insoluble, flexible hydrogel. About 20% of the FGF-2molecules were released from the FGF-2-incorporated chitosan hydrogel into phosphate buffered saline (PBS) within 1 day, after which no further significant release occurred under in vitro non-degradation conditions of the hydrogel. The FGF-2molecules retained in the chitosan hydrogel remained biologically active, and were released from the chitosan hydrogel upon the in vivo biodegradation of the hydrogel. In order to evaluate its accelerating effect on wound healing, full thickness skin incisions were made on the back of healing-impaired diabetic (db/db) mice and their normal (db/+) littermates. Application of the chitosan hydrogel significantly induced wound contraction and accelerated wound closure in both db/db and db/+ mice. However, the addition of FGF-2 in the chitosan hydrogel further accelerated wound closure in db/db mice, although not in db/+ mice. Histological examination also has demonstrated an advanced granulation tissue formation, capillary formation and epithelialization in wounds treated with FGF-2-incorporated chitosan hydrogels in db/db mice.     

Wound healing properties of PVA/starch/chitosan hydrogel membranes with nano Zinc oxide as antibacterial wound dressing material

In this work, hydrogel membranes were developed based on poly vinyl alcohol (PVA), starch (St), and chitosan (Cs) hydrogels with nano Zinc oxide (nZnO). PVA/St/Cs/nZnO hydrogel membranes were prepared by freezing-thawing cycles, and the aqueous PVA/St solutions were prepared by dissolving PVA in distilled water. After the dissolution of PVA, starch was mixed, and the mixture was stirred. Then, chitosan powder was added into acetic acid, and the mixture was stirred to form a chitosan solution. Subsequently, Cs, St and PVA solutions were blended together to form a homogeneous PVA/St/Cs ternary blend solution. Measurement of Equilibrium Swelling Ratio (ESR), Water Vapor Transmission Test (WVTR), mechanical properties, scanning electron microscopy (SEM), MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay, antibacterial studies, in vivo wound healing effect and histopathology of the hydrogel membranes were then performed. The examination revealed that the hydrogel membranes were more effective as a wound dressing in the early stages of wound healing and that the gel could be used in topic applications requiring a large spectrum of antibacterial activity; namely, as a bandage for wound dressing.     

Photocrosslinkable chitosan as a biological adhesive

A photocrosslinkable chitosan to which both azide and lactose moieties were introduced (Az-CH-LA) was prepared as a biological adhesive for soft tissues and its effectiveness was compared with that of fibrin glue. Introduction of the lactose moieties resulted in a much more water-soluble chitosan at neutral pH. Application of ultraviolet light (UV) irradiation to photocrosslinkable Az-CH-LA produced an insoluble hydrogel within 60 s. This hydrogel firmly adhered two pieces of sliced ham with each other, depending upon the Az-CH-LA concentration. The binding strength of the chitosan hydrogel prepared from 30-50 mg/mL of Az-CH-LA was similar to that of fibrin glue. Compared to the fibrin glue, the chitosan hydrogel more effectively sealed air leakage from pinholes on isolated small intestine and aorta and from incisions on isolated trachea. Neither Az-CH-LA nor its hydrogel showed any cytotoxicity in cell culture tests of human skin fibroblasts, coronary endothelial cells, and smooth muscle cells. Furthermore, all mice studied survived for at least 1 month after implantation of 200 microL of photocrosslinked chitosan gel and intraperitoneal administration of up to 1 mL of 30 mg/mL of Az-CH-LA solution. These results suggest that the photocrosslinkable chitosan developed here has the potential of serving as a new tissue adhesive in medical use.     

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。.     

Polyelectroylte complex composed of chitosan and sodium alginate for wound dressing application.

Drug-impregnated polyelectrolyte complex (PEC) sponge composed of chitosan and sodium alginate was prepared for wound dressing application. The morphological structure of this wound dressing was observed to be composed of a dense skin outer layer and a porous cross-section layer by scanning electron microscopy (SEM). Equilibrium water content and release of silver sulfadiazine (AgSD) could be controlled by the number of repeated in situ PEC reactions between chitosan and sodium alginate. The release of AgSD from AgSD-impregnated PEC wound dressing in PBS buffer (PH = 7.4) was dependent on the number of repeated in situ complex formations for the wound dressing. The antibacterial capacity of AgSD-impregnated wound dressing was examined in agar plate against Pseudomonas aeruginosa and Staphylococcus aureus. From the behavior of antimicrobial release and the suppression of bacterial proliferation, it is thought that the PEC wound dressing containing antimicrobial agents could protect the wound surfaces from bacterial invasion and effectively suppress bacterial proliferation. In the cytotoxicity test, cellular damage was reduced by the controlled released of AgSD from the sponge matrix of AgSD-medicated wound dressing. In vivo tests showed that granulation tissue formation and wound contraction for the AgSD plus dihydroepiandrosterone (DHEA) impregnated PEC wound dressing were faster than any other groups.     

Fabrication and characterization of a sponge-like asymmetric chitosan membrane as a wound dressing

A novel asymmetric chitosan membrane has been prepared by immersion-precipitation phase-inversion method and evaluated as wound covering. This new type of chitosan wound dressing which consists of skin surface on top-layer supported by a macroporous sponge-like sublayer was designed. The thickness of the dense skin surface and porosity of sponge-like sublayer could be controlled by the modification of phase-separation process using per-evaporation method. The asymmetric chitosan membrane showed controlled evaporative water loss, excellent oxygen permeability and promoted fluid drainage ability but could inhibit exogenous microorganisms invasion due to the dense skin layer and inherent antimicrobial property of chitosan. Wound covered with the asymmetric chitosan membrane was hemostatic and healed quickly. Histological examination confirmed that epithelialization rate was increased and the deposition of collagen in the dermis was well organized by covering the wound with this asymmetric chitosan membrane. The results in this study indicate that the asymmetric chitosan membrane thus prepared could be adequately employed in the future as a wound dressing.     

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。     

负压封闭引流及皮片移植修复胫腓骨骨折的皮肤软组织缺损

背景：传统的治疗胫腓骨骨折合并皮肤软组织缺损的方法是行简单外固定,创面清创换药待感染控制、肉芽生长旺盛后植皮或皮瓣转移,这种方法不仅费用高、痛苦大、住院时间长,而且有感染扩散、周围组织进一步坏死,最后不得不截肢的可能。 目的：探讨封闭负压引流加外固定架修复胫腓骨骨折并皮肤缺损的临床疗效。 方法：选择本溪市中心医院2009年1月至2013年9月收治胫腓骨骨折皮肤软组织缺损患者38例,皮肤缺损面积>5 cm2,在骨折外固定后给予彻底清创,再行封闭负压引流技术治疗5-7 d,待肉芽组织生长、创面新鲜后行中厚皮片植皮治疗。并回顾性选择15例未采用封闭负压引流治疗的类似病例作为对照组,对其感染控制率及伤口愈合时间等进行比较。 结果与结论：引流5-7 d后去除封闭负压引流敷料,伤口感染得到控制,局部创面肉芽组织生长良好,创面及骨折均如期愈合,无骨髓炎及截肢的发生。38例患者治愈23例,显效12例,无效3例,总有效率为92%,与对照组53%的总有效率相比差异有显著性意义(P < 0.05)。证实封闭负压引流可以彻底清除创面的分泌物和坏死组织,改善局部微循环和消除感染,联合外固定支架和植皮是治疗胫腓骨骨折并软组织缺损的一种简便有效方法。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

Performance of an in situ formed bioactive hydrogel dressing from a PEG-based hyperbranched multifunctional copolymer

Hydrogel dressings have been widely used for wound management due to their ability to maintain a hydrated wound environment, restore the skin’s physical barrier and facilitate regular dressing replacement. However, the therapeutic functions of standard hydrogel dressings are restricted. In this study, an injectable hybrid hydrogel dressing system was prepared from a polyethylene glycol (PEG)-based thermoresponsive hyperbranched multiacrylate functional copolymer and thiol-modified hyaluronic acid in combination with adipose-derived stem cells (ADSCs). The cell viability, proliferation and metabolic activity of the encapsulated ADSCs were studied in vitro, and a rat dorsal full-thickness wound model was used to evaluate this bioactive hydrogel dressing in vivo. It was found that long-term cell viability could be achieved for both in vitro (21 days) and in vivo (14 days) studies. With ADSCs, this hydrogel system prevented wound contraction and enhanced angiogenesis, showing the potential of this system as a bioactive hydrogel dressing for wound healing.     

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.     

负压封闭引流联合对流冲洗修复Fournier坏疽创面的疗效研究

目的通过分组对照,研究负压封闭引流(VSD)联合对流冲洗治疗Fournier坏疽的效果。 方法选取新疆维吾尔自治区人民医院2012年1月至2016年9月收治的16例Fournier坏疽患者,其中4例因VSD需自费纳入单纯换药组,另12例按照随机数字表法分为单纯VSD组6例和VSD联合对流冲洗组6例。所有患者经抗感染、控制血糖治疗后行Ⅰ期清创手术。单纯VSD组：根据创面大小及形态将负压材料剪成合适形状,充分接触并填满创面残腔,确保无残留死腔,封闭创面后负压接医院中心负压进行持续吸引,负压为150 mmHg(1 mmHg＝0.133 kPa);VSD联合对流冲洗组：在单纯VSD组处理基础上联合0.9%氯化钠溶液通过输液器冲洗创面;清创换药组：对创面进行仔细清创,并用0.9%氯化钠溶液、3%过氧化氢溶液反复对创面进行冲洗,尽量保持创面清洁后,乳酸依沙吖啶纱布填充创面后敷料覆盖。对各组的创面细菌清除率、Ⅱ期缝合术式、平均创面封闭时间、住院总时间、患者满意情况、VSD使用个数及VSD堵管率等进行统计分析,评价3组治疗方案的疗效。对数据进行单因素方差分析、LSD法及χ²检验。 结果治疗后,单纯VSD组可见创面肉芽组织生长较好;VSD联合对流冲洗组创面基本被鲜红肉芽组织覆盖;清创换药组创面可见肉芽组织散在生长,创基仍可见坏死组织及分泌物附着,创周皮肤炎症反应较重。3组患者创面细菌清除率比较,差异有统计学意义(F＝41.707,P<0.05)。清创换药组创面细菌清除率为(58.7±4.5)%,明显低于单纯VSD组[(79.8±5.6)%]、VSD联合对流冲洗组[(93.6±6.9)%],差异均有统计学意义(t＝5.522、9.133,P值均小于0.05);单纯VSD组创面细菌清除率也明显低于VSD联合对流冲洗组,差异有统计学意义(t＝4.038,P＝0.001)。单纯VSD组5例Ⅱ期行拉拢缝合联合植皮封闭创面,1例腹股沟区创周皮瓣红肿明显,拉拢缝合后切口局部持续较多分泌物渗出,加强清创换药后切口逐渐愈合;VSD联合对流冲洗组患者Ⅱ期缝合采用直接拉拢缝合即基本封闭创面,创面愈合良好;清创换药组1例Ⅱ期行直接拉拢缝合联合局部植皮,皮片部分成活,剩余3例行局部皮瓣转移修复术加游离植皮术封闭创面。3组患者平均创面封闭时间比较,差异有统计学意义(F＝25.989,P<0.05);清创换药组的平均创面封闭时间明显大于单纯VSD组、VSD联合对流冲洗组,差异均有统计学意义(t＝4.931、7.195,P值均小于0.05);单纯VSD组平均创面封闭时间也明显大于VSD联合对流冲洗组,差异有统计学意义(t＝2.655,P＝0.018)。3组患者住院总时间比较,差异有统计学意义(F＝25.707,P<0.05);清创换药组的住院总时间为(38.3±9.3) d,明显大于单纯VSD组[(22.3±3.4) d]、VSD联合对流冲洗组[(16.7±2.0) d],差异均有统计学意义(t＝5.263、7.106,P值均小于0.05);单纯VSD组住院总时间也明显大于VSD联合对流冲洗组,差异有统计学意义(t＝2.160,P＝0.047)。单纯VSD组堵管率为44.4%(12/27),VSD联合对流冲洗组堵管率为15.8%(3/19),两组比较差异有统计学意义(χ²＝4.167,P＝0.041)。单纯VSD组患者治疗期间虽然也无明显疼痛,但费用较高;VSD联合对流冲洗组创面愈合良好,患者满意度最高;清创换药组患者换药过程疼痛剧烈,住院时间长,后期创面封闭效果不甚满意。 结论VSD联合对流冲洗能快速稀释引流创面分泌物,减轻创面感染,有效解决堵管发生,保障引流通畅,为创面愈合提供良好的生长环境,值得在临床中推广开来。