异种皮覆盖薄中厚与刃厚微粒皮皮浆移植修复烧伤创面的对比

背景:采用自体微粒皮移植异体皮覆盖已成为近来修复特重度烧伤患者创面的主要手段。由于异体皮来源极为困难,因此,临床上采用异种皮(猪皮)或人工皮作为载体来覆盖创面。目的:观察薄中厚微粒皮皮浆移植异种皮覆盖修复烧伤创面的疗效及创面愈合后的皮肤质量,并与刃厚微粒皮皮浆移植异种皮覆盖的临床疗效进行对比。方法:选取特重度具有双侧肢体烧伤的患者36例,采用自身对照的方法,选择可供对比的创面42对,其中关节部位32对。每例患者选取1至2对肢体烧伤程度较为相同的Ⅲ度切痂创面进行对比。在异种皮覆盖下,试验组采用薄中厚微粒皮皮浆涂抹移植修复烧伤创面,对照组采用刃厚微粒皮皮浆涂抹移植修复烧伤创面,两组供皮区与受皮区面积之比相同(所有患者扩张比控制在1∶8-1∶12)。观察创面愈合时间、移植后半年至2年创面愈合后的瘢痕增生程度、关节部位需整复手术的比率,对手术切除的瘢痕按温哥华瘢痕量表总评分进行对比分析。结果与结论:试验组创面平均愈合时间(44.7±1.24)d,明显短于对照组创面平均愈合时间(49.6±1.41)d(P0.05)。试验组移植后半年至2年创面愈合后的瘢痕增生程度轻于对照组:重度瘢痕增生的比率明显小于对照组(P0.05),轻度瘢痕增生的比率明显大于对照组(P0.01),两组中度瘢痕增生的比率相近(P0.05)。试验组关节部位需整复手术的比率为38%,明显低于对照组59%(P0.01)。试验组手术切取瘢痕的温哥华瘢痕量表总评分明显低于对照组(P0.05)。提示在异种皮覆盖下,通过增加微粒皮厚度,采用薄中厚微粒皮浆移植是修复大面积全层皮肤烧伤的较好方法,可获得较好的创面愈合质量。     

人脐带间充质干细胞促进微粒皮复合异体皮移植修复兔皮肤创面的实验研究

目的观察人脐带间充质干细胞（hUC-MSC）与大耳兔自体微粒皮复合同种异体皮移植促进修复其皮肤缺损创面的效果。方法取成年日本大耳兔8只,构建兔皮肤缺损模型,每2只兔交换移植反削断层皮,异体真皮面均匀黏附兔自体微粒皮。头侧创面为hUC-MSC移植组（A组）、尾侧创面为PBS液空白对照组（B组）。术后21 d观察创面情况,计算创面愈合率,进行统计学分析;术后28 d切取创面愈合区域组织,对标本行苏木精-伊红染色观察。结果术后21 d创面愈合率A组（85.1±4.0）%,高于B组（79.5±4.3）%,两组比较差异有统计学意义（P〈0.05）。取材病理学观察可见两组组织均缺少皮肤附件;A组表皮层可发现表皮钉突样结构,而B组表皮层底部平坦,与基底结合较为疏松。结论推测hUC-MSC可促进创面微粒皮生长、扩展,缩短创面愈合时间,提高愈合质量。     

同种异体皮在皮肤软组织严重毁损性创面修复中的应用

目的探讨同种异体皮覆盖急性毁损性创面,提高患者救治成功率及促进创面愈合的可行性。方法 回顾性分析56例急诊住院治疗皮肤软组织严重毁损性患者的临床病例,按治疗方法分组:急诊清创后同种异体皮覆盖创面,待二期修复创面的28例为治疗组;清创后一期皮瓣、植皮封闭创面的28例设为对照组,观察两组患者的救治成功率和创面封闭时间。结果 两组救治成功率分别为96.43%和78.57%,差异具有统计学意义(P0.05);实验组创面治愈时间(16.17±1.87)d与实验组(21.71±3.95)d,差异具有统计学意义(P0.01)。结论 皮肤软组织严重毁损性损伤急诊手术应以稳定患者全身情况为重点,创面使用同种异体皮覆盖待二期修复,可降低急诊手术的风险性,提高患者救治成功率,缩短治疗周期。     

自体微粒皮与异体脱细胞微粒真皮混合移植对大鼠创面细胞骨架蛋白与新生血管化的影响

目的探讨自体微粒皮与异体脱细胞微粒真皮混合移植对创面愈合的影响,并对有关机理做进一步研究。方法用雄性Wistar大鼠制做异体脱细胞真皮,90只雌性SD大鼠背部建立全层皮肤损伤模型,分为A、B、C、D、E组,每组18只,A组为自体微粒皮组,B组为异体脱细胞微粒真皮组,C、D、E组为自体微粒皮与异体脱细胞微粒真皮按不同的比例（C组为1∶1,D组为1∶0.5,E组为1∶0.25）混合移植（统称为混合移植组）,比较各组的创面愈合率、微血管计数及细胞骨架蛋白（desmin）的表达。结果 （1）移植后2、3周,混合移植组创面愈合率均高于A组和B组,E组移植后2、3周创面愈合率分别为（88.00±5.71）%和（96.18±6.62）%,高于C组（79.81±7.07）%和（86.76±3.35）%（P〈0.05）;（2）移植后2、3周混合移植组微血管数均明显高于A组、B组（P〈0.05）,移植后2周,E组、D组的血管数（35.67±1.53）、（34.33±1.53）明显多于C组（P〈0.05）。（3）细胞骨架蛋白在创面形成后表达上调,混合移植组细胞骨架蛋白的表达高于A组（P〈0.05）,尤以D组、E组明显。结论自体微粒皮与脱细胞微粒真皮混合移植创面愈合率高于自体微粒皮移植,且自体微粒皮与脱细胞微粒真皮混合移植的面积比例按1∶0.25混合移植效果最佳,这可能与创面血管化进程加快,及细胞骨架蛋白的适度表达有关。     

异种羊脱细胞真皮基质与白体微粒皮复合移植后创面愈合及COX-2、VEGF的表达研究

目的制备异种羊脱细胞真皮基质（ADM）,观察异种羊ADM与白体微粒皮复合移植的组织学变化,以及免疫组化法检测环氧化酶-2（COX-2）、血管内皮生长因子（VEGF）在复合移植过程中的表达。方法用0．25％胰蛋白酶和O．5％曲拉通（TritonX-100）溶液联合脱细胞法制备异种羊ADM。以48只Wistar大鼠为动物模型随机分为2组,每组各24只,背部做4cm×3cm全层皮肤缺损,分组采用羊ADM＋自体微粒皮＋异体皮（实验组）及自体微粒皮＋异体皮（对照组）覆盖,术后2、4、6周观察植皮区愈合情况,检测创面收缩率;同时,在以上不同时间段处死大鼠做组织病理学观察及免疫组化检查。结果（1）通过实验可成功制备出合格的异种羊ADM,脱细胞异种皮的镜下观察可见基质中的表皮已经完全除去,胶原纤维粗细均匀,排列规则,没有细胞成份存在。（2）进行移植术后,观察6周,两组皮片创面基本愈合,两组创面收缩率差异具有统计学意义（P〈0．05）,实验组术区收缩程度低,组织学检查可见成纤维细胞和血管长入,胶原纤维、弹力纤维结构排列规则;对照组创面收缩明显,组织学检查见成纤维细胞和血管无规则生长,胶原纤维、弹力纤维结构排列紊乱。两组大鼠创面COX-2、VEGF表达差异无统计学意义（P〉0．05）。结论异种羊ADM在彻底脱除了基质中有免疫原性的细胞成分的同时,义保留了组织的基本结构,成为极低抗原性的真皮支架,是一种良好的真皮替代物;异种羊ADM与自体微粒皮复合移植后外观和功能优于白体微粒皮移植;COX-2,VEGF可能参与了创面的修复。     

脱细胞异体真皮基质与自体微粒皮混合移植关节部位的临床应用

目的观察脱细胞异体真皮基质与自体微粒皮混合移植后创面修复情况。方法将18例烧伤总面积50％TBSA以上，Ⅲ度烧伤面积20％，TBSA以上患者随机分为两组。治疗组：9例患者Ⅲ度烧伤创面早期切痂，15个关节部位采用38块脱细胞真皮基质移植固定，在异体皮的真皮面上均匀涂布备好的微粒皮，覆盖于脱细胞真皮基质上，同一肢体其余创面常规用自体微粒皮加异体皮移植缝合包扎固定。对照组：9例12个肢体使用传统微粒皮移植，观察16个关节部位，微粒皮与创面比例为1：13．1：8。结果治疗组脱细胞异体真皮基质与微粒皮混合移植皮肤成活率为92％，对照组微粒皮成活率94％。随访3—17个月，治疗组残余创面发生率为13．3％，对照组为50％，有显著性差异。皮肤弹性、关节活动度等愈合质量治疗组优于对照组。结论应用脱细胞真皮基质与自体微粒皮混合移植，效果明显优于传统的微粒皮移植，具有较好的临床应用前景。     

人工真皮移植修复儿童严重创伤创面

背景:近年来组织工程学取得巨大进展,皮肤组织工程尤为引人注目。人工真皮(PELNAC)相对应用较广泛,但报道以成人为主,缺乏修复儿童创面的报道。目的:探讨人工真皮作为儿童严重创伤创面真皮覆盖物的临床效果。方法:回顾性总结分析22例创面负压引流、人工真皮复合自体刃厚皮片或薄中厚皮片移植覆盖儿童严重创伤创面(实验组)的治疗效果,并与19例创面负压引流、创面肉芽培养、自体刃厚皮片或薄中厚皮片移植于同等创面(对照组)的治疗效果进行对比。分析评价指标包括人工真皮的存活率、创面完全覆盖所需的手术次数、植皮后创面完全愈合时间、随访创面移植区域的色泽、质地、皮下丰满度、瘢痕增生情况以及关节功能影响等。结果与结论:人工真皮移植后10-14 d存活率达90%以上。实验组2例第二次刃厚皮片移植,对照组8例第二次刃厚皮片移植,实验组创面植皮存活率优于对照组(P0.05)。实验组植皮后创面完全愈合的平均时间为(13.86±3.09)d,对照组为(19.10±4.62)d,实验组平均植皮后创面完全愈合时间短于对照组(P0.05)。经超过10个月随访,实验组的植皮区色泽、弹性优于对照组;实验组创面移植区域较对照组真皮部分皮下丰满度良好、瘢痕增生明显较轻;实验组关节功能受到不同程度影响5例,对照组关节功能受到影响10例,两组差异有显著性意义(P0.05)。提示人工真皮抗感染力强、存活率高。将人工真皮应用于儿童严重创伤创面,与创面负压引流、培养肉芽及自体刃厚皮片或薄中厚皮片移植相比,能缩短创面植皮后愈合时间,提高愈合创面的质量,减少对关节功能的影响。     

自体异体皮片混合移植现状与展望

皮片混合移植法的提出对于大面积深度烧伤患者的救治具有划时代的重要意义,使利用有限的自体皮片在较短期内修复大面积深度烧伤创面成为可能,降低了因创面长时间裸露导致超高代谢、感染等并发症的发生,而且有利于改善创面修复质量。皮片混合移植技术主要包括大张异体（种）皮开洞自体小皮片嵌植、砌砖式自体异体皮片混合移植、自体微粒皮片移植覆盖大张异体皮、自体异体表皮细胞混合移植等等。     

异种羊脱细胞真皮基质与自体微粒皮复合移植后创面愈合及COX-2、VEGF的表达研究

目的 制备异种羊脱细胞真皮基质(ADM),观察异种羊ADM与自体微粒皮复合移植的组织学变化,以及免疫组化法检测环氧化酶-2(COX-2)、血管内皮生长因子(VEGF)在复合移植过程中的表达.方法 用0.25%胰蛋白酶和0.5%曲拉通(Tritonx-100)溶液联合脱细胞法制备异种羊ADM.以48只wistar大鼠为动物模型随机分为2组,每组各24只,背部做4 cm×3 cm全层皮肤缺损,分组采用羊ADM+自体微粒皮+异体皮(实验组)及自体微粒皮+异体皮(对照组)覆盖,术后2、4、6周观察植皮区愈合情况,检测创面收缩率;同时,在以上不同时间段处死大鼠做组织病理学观察及免疫组化检查.结果 (1)通过实验可成功制备出合格的异种羊ADM,脱细胞异种皮的镜下观察可见基质中的表皮已经完全除去,胶原纤维粗细均匀,排列规则,没有细胞成份存在.(2)进行移植术后,观察6周,两组皮片创面基本愈合,两组创面收缩率差异具有统计学意义(P<0.05),实验组术区收缩程度低,组织学检查可见成纤维细胞和血管长人,胶原纤维、弹力纤维结构排列规则;对照组创面收缩明显,组织学检查见成纤维细胞和血管无规则生长,胶原纤维、弹力纤维结构排列紊乱.两组大鼠创面COX-2、VEGF表达差异无统计学意义(P>0.05).结论 异种羊ADM在彻底脱除了基质中有免疫原性的细胞成分的同时,又保留了组织的基本结构,成为极低抗原性的真皮支架,是一种良好的真皮替代物;异种羊ADM与自体微粒皮复合移植后外观和功能优于自体微粒皮移植;COX-2,VEGF可能参与了创面的修复.     

微型皮片移植方法在大面积深度烧伤中的应用

临床医师使用外科方法清除失去活力的烧伤坏死组织,并迅速封闭广泛开放的创面,已成为现代大面积深度烧伤救治的常用方法,也是预防烧伤严重感染的根本措施。但在治疗时,突出的矛盾是患者自体皮源不足,希望用少量甚至极少量的自体皮肤移植修复大面积深度创面成为临床工作者不断探索的命题。在皮肤移植的发展史上,经历了点状植皮、邮票植皮、网状植皮、筛状植皮、自体微粒皮或皮浆和异体皮混合移植、Meek微型皮片移植乃至自体细胞培养复合移植等多种方法,这些方法在实际使用中各有其优缺点和局限性。其中,自体微粒皮移植、自体皮浆移植及Meek植皮术是当前大面积深度烧伤患者常用的微型皮片移植方法,基本上解决了大面积深度烧伤患者供皮面积小而植皮面积大的矛盾。自体微粒皮移植需要异体皮肤或异种皮肤作为载体覆盖才能完成,包括大张异体皮覆盖自体微粒皮移植和大张异种皮覆盖自体微粒皮移植。自体皮浆移植尽管操作简单方便,但对创面条件要求更高。自体微粒皮移植及自体皮浆移植这两种植皮技术作为特大面积深度烧伤患者的传统创面修复方法,尽管受诸多限制,目前应用仍较广泛。Meek植皮技术,以其独特的皮片扩张技术和机械化操作大大改变了传统的徒手操作方式,目前已成为修复大面积深度烧伤创面较为理想的方法。     

脱细胞异体真皮与自体刃厚皮片联合移植修复足踝部非负重区创面的临床研究

目的探讨脱细胞异体真皮与自体刃厚皮片联合移植在足踝部非负重区创面修复中的疗效。 方法采用回顾性队列研究方法,分析2015年1月至2021年3月上海交通大学医学院附属第六人民医院收治的51例足踝部非负重区创面患者。按照治疗方式不同进行分组,行复合皮移植治疗患者24例,设为复合皮移植组;采用自体全厚皮片移植治疗患者27例设为全厚皮移植组。患者创面清创后,复合皮移植组用脱细胞异体真皮覆盖创面,其上覆盖自体刃厚皮片联合移植,全厚皮移植组使用自体全厚皮片覆盖创面。术后评估2组患者的皮片成活率、再植皮率、创面愈合时间以及供皮区愈合时间。术后随访12个月,末次随访时进行美国足踝外科医师协会(AOFAS)踝关节功能评估及温哥华瘢痕量表(VSS)评分。数据比较采用t检验、Wilcoxon检验、卡方检验及Fisher精确检验。 结果术后评估,复合皮移植组和全厚皮移植组的皮片最终均存活。全厚皮移植组因术后皮片部分坏死的再植皮率为22.2%(6/27),高于复合皮移植组的4.2%(1/24),但差异无统计学意义(P＝ 0.103)。复合皮移植组创面愈合时间为17.0(15.8, 18.0)d,显著短于全厚皮移植组的24.0(18.0, 38.0)d,差异有统计学意义(Z＝ －4.222, P< 0.01)。2组患者供区愈合时间差异无统计学意义(P> 0.05)。复合皮移植组的AOFAS踝关节功能评分为93.0(92.0, 95.0)分,显著优于全厚皮移植组的87.0(84.0, 91.5)分,差异有统计学意义(Z＝ 3.574, P< 0.01)。复合皮移植组VSS评分为5.0(4.0, 6.0)分,优于全厚皮移植组7.0(5.5, 8.5)分,差异有统计学意义(Z＝－3.823, P< 0.01)。 结论脱细胞异体真皮与自体刃厚皮片联合移植可有效修复足踝部非负重区皮肤软组织缺损,显著促进创面愈合,术后瘢痕较轻且可保持良好的踝关节功能。     

银离子水胶体油纱结合自黏性聚氨酯泡沫敷料对供皮区创面愈合的疗效研究

目的 发现并改进一种促进大面积取皮后供皮区创面愈合的治疗方法.方法 将2014年1月至2015年12月需要在大腿上切取中厚皮片的患者共40例,随机分为试验组和对照组.取皮术后试验组采用银离子水胶体油纱和自黏性聚氨酯泡沫敷料覆盖创面;对照组采用传统的凡士林油纱和无菌纱布、棉垫覆盖创面,并用绷带加压包扎.对比术后局部感染的情况、首次换药时的疼痛评分、术后至完全愈合期间的换药次数、完全愈合所需的时间及术后两周时未愈合面积的百分比,并用SPSS17.0做统计学分析.结果 试验组无一例感染,对照组有两例发生感染,创面分泌物培养均为铜绿假单胞菌,经换药治疗痊愈.试验组在首次换药时的疼痛评分、完全愈合前的换药次数及愈合时间上均显著优于对照组,其差异均有统计学意义(U=81.5,P=0.001;U=109.5,P=0.011;t=0.769,P＜0.001).结论 采用银离子水胶体油纱结合自黏性聚氨酯泡沫敷料有助于促进供皮区创面愈合,减少患者痛苦,且该方法换药次数少,操作简便,术后两周内供皮区基本愈合,值得进一步推广使用.     

A bilayer composite composed of TiO2-incorporated electrospun chitosan membrane and human extracellular matrix sheet as a wound dressing

We designed bilayer composites composed of an upper layer of titanium dioxide (TiO₂)-incorporated chitosan membrane and a sub-layer of human adipose-derived extracellular matrix (ECM) sheet as a wound dressing for full-thickness wound healing. The dense and fibrous top layer, which aims to protect the wound from bacterial infection, was prepared by electrospinning of chitosan solution followed by immersion in TiO₂ solution. The sponge-like sub-layer, which aims to promote new tissue regeneration, was prepared with acellular ECM derived from human adipose tissue. Using a modified drop plate method, there was a 33.9 and 69.6% reduction in viable Escherichia coli and Staphylococcus aureus on the bilayer composite, respectively. In an in vivo experiment using rats, the bilayer composites exhibited good biocompatibility and provided proper physicochemical and compositional cues at the wound site. Changes in wound size and histological examination of full-thickness wounds showed that the bilayer composites induced faster regeneration of granulation tissue and epidermis with less scar formation, than control wounds. Overall results suggest that the TiO₂-incorporated chitosan/ECM bilayer composite can be a suitable candidate as a wound dressing, with an excellent inhibition of bacterial penetration and wound healing acceleration effects.     

Development of alginate gel dressing

Alginate-based wound dressing materials have been widely used to promote wound healing and to reduce blood loss from wounds. However, recently a few drawbacks of well-established commercial alginate dressings have been reported. Therefore, we tried to develop a new alginate dressing to reduce the drawbacks. First, four new dressings with different calcium content were prepared, and the cytotoxicity of these four materials, and Kaltostat and Sorbsan, was tested in vitro by culture of fibroblasts with their extracts. Second, full-thickness wounds in pigs were used for the evaluation of wound healing in vivo. Finally, a newly developed alginate dressing was used clinically for treatment of split-thickness skin graft donor sites. The extract medium from ALG3, ALG4, Kaltostat, and Sorbsan induced a significant inhibitory effect on proliferation of fibroblasts. As for wound closure rate, the ALG2-covered wounds had the smallest wound area on day 15. Histologically, foreign-body reaction was least in ALG2-treated wounds. In a clinical study, the main drawback of ALG2 was leakage of wound exudate due to dissolution of the dressing material. However, the transparency of moistened ALG2 allowed easy evaluation of the wound, and after healing it was easy to remove ALG2 from the wound without injury to the reepithelialized skin because ALG2 was relatively nonadherent to the wound.     

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。.     

富血小板血浆联合微粒皮移植在高原地区老年慢性小创面中的临床研究

目的探究在高原地区老年慢性小创面治疗中使用富血小板血浆(PRP)联合微粒皮移植的治疗效果。 方法选取2018年2月至2022年2月青海省人民医院烧伤整形科收治的老年慢性小创面患者60例。根据患者入院时间不同将患者分为观察组和对照组,观察组采用PRP联合微粒皮移植,对照组采用PRP联合刃厚邮状皮移植。采集患者的外周静脉血,采用二次离心法制备PRP;2组患者均于局部浸润麻醉下应用电动取皮机自大腿前内侧根据创面需要取合适大小刃厚皮片,皮片厚度约0.2 mm,观察组供受区比例为1∶4~1∶8,将所取皮片剪碎后切割成直径<1 mm²的微粒皮备用;对照组供受区比例为1∶1~1∶2,将所取皮片制备为大小约1 cm×1 cm的刃厚邮状皮备用。创面清创、止血后,观察组将制备好的微粒皮均匀涂抹在创面后以PRP填充创面,用聚氨酯泡沫敷料或凡士林纱布覆盖创面避免PRP流失及失活,清洁敷料覆盖并固定;对照组将制备好的PRP填充于创面,再将制备好的刃厚邮状皮片移植于PRP之上,用凡士林或聚氨酯泡沫敷料覆盖清洁敷料加压包扎。2组术后均常规行抗感染等治疗,术后第6、11、16、21、26天创面换药,直至创面完全愈合。术后第21天,统计2组患者的治疗有效率;统计2组患者的创面愈合时间;创面愈合后6个月,以温哥华瘢痕评估量表(VSS)对2组患者的瘢痕情况进行评估。数据比较采用Mann-Whitney U检验和χ²检验。 结果术后第21天,观察组治疗有效27例,无效3例,治疗有效率为90.00%;对照组治疗有效20例,无效10例,治疗有效率为66.67%,2组比较差异有统计学意义(χ²＝6.278,P＝0.043)。观察组创面愈合时间为为26.0(24.0, 27.0) d,短于对照组[43.0(39.8, 47.3) d],2组比较差异有统计学意义(Z＝－6.531,P<0.05)。创面愈合后6个月,观察组VSS评分中色素沉着、瘢痕厚度、血管分布和柔韧性评分分别为0(0, 0)、0(0, 0)、0(0, 0)、1(0, 1)分,均分别低于对照组[2.0(1.0, 2.3)、1.5(0.8, 2.0)、1(1, 2)、2(1, 3)分],2组比较差异均有统计学意义(Z＝－6.310、－4.838、－5.624、－4.431,P<0.05)。 结论在高原地区,对于老年慢性小创面的治疗,PRP联合微粒皮移植的创新技术具有提高治疗有效率、缩短创面愈合时间的疗效,为患者提供更多治愈的选择性。     

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.     

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.     

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.