枯草芽胞杆菌喷雾剂对家兔皮肤创伤愈合的影响

目的 :观察枯草芽胞杆菌喷雾剂对家兔皮肤创伤愈合的影响。方法 :采用家兔皮肤创伤为模型 ,连续给药 6 d,第 11天测定创面面积 ,并于第 17天记录创面愈合数。结果 :枯草芽胞杆菌喷雾剂高剂量组和磺胺嘧啶银组创面面积显著小于空白对照组 ( P<0 .0 5 ) ;枯草杆菌喷雾剂的愈合率显著高于空白对照组( P<0 .0 5 )。结论 :枯草芽胞杆菌喷雾剂能够缩小家兔创面愈合 ,增加创面愈合率     

创面生物活性玻璃修复材料促进家猪创面愈合的实验研究

目的:观察创面生物活性玻璃修复材料对家猪皮肤创面的促愈合作用。方法:选择14头家猪,随机分成7组,每组2头,在每头猪的脊柱两旁制造3个4×4cm的全层皮肤缺损的创面模型,每头猪6个创面又分成实验组和空白对照组,于试验后每天观察创面愈合情况,第1、3、7、14、21、28、35天图像分析计算创面愈合率,并同时取创面组织行组织学染色,观察各组材料对家猪皮肤全层缺损创面愈合的影响。结果:在涂材料的实验组和空白对照组创面愈合时间分别是23.19±1.27d、29.52±1.54d两组组间比较,具有统计学意义(P<0.05);实验组的创面愈合率在各时间段均高于空白对照组,差异有统计学意义(P<0.05);组织学观察实验组的上皮化程度、表皮生长、成纤维细胞、毛细血管数量均好于空白对照组。结论:创面生物活性玻璃修复材料对家猪皮肤创面愈合具有促进作用,可作为一种新型的促愈合覆盖材料进一步研究。     

蝇蛆油促进大鼠皮肤机械损伤愈合作用及机制研究

目的:本文拟研究蝇蛆油对皮肤机械损伤的治疗作用及作用机制。方法:SD大鼠随机分为正常组、模型组、蝇蛆油组和重组牛碱性成纤维细胞生长因子(rb-bFGF)凝胶组,制作大鼠皮肤机械性损伤模型,在不同时间点采集样本,检测创面愈合率、创面愈合时间、血管内皮生长因子(VEGF)含量、丙二醛(MDA)和超氧化物歧化酶(SOD)水平,并检测组织中胶原蛋白Ⅰ、胶原蛋白Ⅲ、血小板衍生因子(PDGF)和细胞角蛋白19(CK19)表达情况。结果:模型组大鼠创面愈合时间为29.5±2.6 d,而蝇蛆油创面愈合时间为22.4±2.8 d,存在显著差异(P0.01)。VEDF含量在模型组和给药组均随着创面愈合时间增加,给药组在第1 d即显著高于模型组(P0.01),并在第21 d达到最大值(2051.5±148.2 ng/L)。模型组大鼠创面组织中MDA含量为6.47±0.92 nmo L/mg,SOD含量为7.52±3.21 U/mg,而蝇蛆油给药组大鼠创面组织中MDA含量为3.42±0.83 nmo L/mg,SOD含量为21.32±2.94 U/mg,存在显著差异(P0.01)。进一步研究发现,与模型组比较,蝇蛆油给药组大鼠创面组织中胶原蛋白Ⅰ、胶原蛋白Ⅲ、PDGF和CK19含量均显著升高(P0.01)。结论:蝇蛆油能够促进机械性损伤皮肤创面愈合,其作用机制可能是通过促进血管生成,抗氧化损伤,促进胶原生成,诱导干细胞形成,从而促进创面愈合。     

创面生物活性玻璃修复材料促进家猪创面愈合的实验研究

目的：观察创面生物活性玻璃修复材料对家猪皮肤创面的促愈合作用。方法：选择14头家猪,随机分成7组,每组2头,在每头猪的脊柱两旁制造3个4×4cm的全层皮肤缺损的创面模型,每头猪6个创面又分成实验组和空白对照组,于试验后每天观察创面愈合情况,第1、3、7、14、21、28、35天图像分析计算创面愈合率,并同时取创面组织行组织学染色,观察各组材料对家猪皮肤全层缺损创面愈合的影响。结果：在涂材料的实验组和空白对照组创面愈合时间分别是23.19±1.27d、29.52±1.54d两组组间比较,具有统计学意义（P〈0.05）;实验组的创面愈合率在各时间段均高于空白对照组,差异有统计学意义（P〈0.05）;组织学观察实验组的上皮化程度、表皮生长、成纤维细胞、毛细血管数量均好于空白对照组。结论：创面生物活性玻璃修复材料对家猪皮肤创面愈合具有促进作用,可作为一种新型的促愈合覆盖材料进一步研究。     

瘦素促进皮肤创伤大鼠胶原合成的实验研究

目的：研究瘦素对创伤大鼠创面组织胶原合成的影响,探讨瘦素促进创伤愈合的作用机制。方法：雄性Wistar大鼠30只,体质量（180±20）g,按体重随机分为：正常组、创伤对照组和瘦素治疗组,用5%Na2S背部脱毛。瘦素治疗组和创伤对照组大鼠于背部制做缺损创面（2.0 cm×2.5 cm）,并分别用瘦素蛋白溶液0.1 ml（含瘦素2.0μg）和等体积生理盐水涂抹,每天一次,连续7 d。之后处死大鼠,取创面组织及正常组大鼠相应部位脱毛皮肤检测皮肤及创面胶原合成相关指标。结果：瘦素治疗组肉芽组织中羟脯氨酸含量（33.92±3.09）mg/g较创伤对照组（29.55±3.59）mg/g显著升高（P〈0.05）,I、Ⅲ型胶原mRNA的水平0.96±0.09、0.09±0.06分别较创伤对照组0.80±0.03、0.08±0.03显著增加（P〈0.05）,I、Ⅲ型胶原的蛋白表达也较创伤对照组显著增强。结论：瘦素通过促进创伤组织I、Ⅲ型胶原的基因表达和胶原蛋白的合成,从而加快肉芽组织的生长,促进创伤组织的修复和愈合。     

冬瓜粗提物对小鼠紫外线晒伤皮肤的修复作用

为探讨冬瓜(Benincasa hispida)粗提物对小鼠紫外线晒伤皮肤的修复作用,建立小鼠紫外线晒伤模型。观察冬瓜粗提物对晒伤小鼠内源性血管内皮生长因子(VEGF)及碱性成纤维细胞生长因子(FGF-2)表达的影响。冬瓜提取物组(浓度均为31 mg/m L),药物组(利多卡因氯已定气雾剂),正常对照组和阴性组(生理盐水),每天2次涂药并观察创面,分别在0、1、3、7、14 d处死小鼠,取皮肤组织,做病理切片,取晒伤组织提取蛋白并检测VEGF、FGF-2的表达状况。3~7 d时,阳性对照组和实验组的VEGF和FGF-2的表达明显高于阴性对照组和正常组,且阳性组与实验组VEGF和FGF-2表达水平有显著差异。病理切片显示实验组炎性细胞和血管数量明显多于阴性对照组,且两组间差异明显。即冬瓜粗提物能提高皮肤组织的生长因子VEGF和FGF-2的表达,促进晒伤皮肤的愈合。     

全蝎软膏对大鼠糖尿病皮肤溃疡创面愈合的效果评价

目的:探讨全蝎软膏治疗糖尿病皮肤创面愈合的作用及其机制。方法:采用SPF级SD大鼠构建糖尿病皮肤溃疡模型,将其随机平均分为对照组、模型组、全蝎软膏组和湿润烧伤膏组。造模后,分别在创面处涂抹全蝎软膏或湿润烧伤膏处理,空白组和模型组用PBS处理,观察和比较各组创面的愈合情况,并收集用药后3 d、7 d、10 d和14 d的创面肉芽组织进行HE染色,通过ELISA及荧光定量PCR检测肉芽组织内碱性成纤维细胞生长因子(bFGF)、血管性假血友病因子(v WF)、肿瘤坏死因子α(TNF-α)与Smad 4基因的表达。结果:成功构建大鼠糖尿病皮肤溃疡模型,成模率为96.15%。创伤后第3 d、7 d、10 d和14 d,各治疗组创面愈合率均显著高于模型组(P0.05),给药14 d时,全蝎软膏组创面愈合率已接近对照组水平。HE染色结果显示与模型组相比,全蝎软膏组中肉芽组织生长较快、毛细血管数量增多且组织纤维化程度较低。ELISA和荧光定量PCR检测结果显示与模型组和湿润烧伤膏组相比,全蝎软膏组肉芽组织内bFGF、v WF含量上调更显著(P0.05),而TNF-α含量与Smad 4 m RNA显著降低(P0.05)。结论:全蝎软膏可促进糖尿病皮肤溃疡创面肉芽组织的生长,可能与其抑制炎症反应并改善血管功能有关。     

人脐带间充质干细胞上清凝胶加速小鼠皮肤创面愈合

目的:探讨人脐带间充质干细胞(hUC-MSCs)上清凝胶对小鼠皮肤创面修复的作用,为临床皮肤创伤提供新的修复方法奠定基础。方法:从新生儿脐带分离出hUC-MSCs并培养,经流式细胞仪检测细胞表面标志物、成骨成脂细胞分化实验以及RT-PCR检测干性相关基因的表达证明其干细胞特性;收集上清液,进行粗提纯及总蛋白浓度检测,制成凝胶剂,用于小鼠背部损伤模型中创面的治疗;于第2、3、6、8、15 d取样,伤口及正常皮肤组织样品分别用于制备组织病理切片及愈合组织相关因子表达的Q-PCR检测。结果:从新生儿脐带分离出的hUC-MSCs其形态、表面标志物符合干细胞特性,具有成骨和成脂诱导分化潜能。实验小鼠皮肤创伤后3 d开始可见各组创面逐渐缩小,伤后15 d创面基本愈合;第5、7 d高剂量组创面愈合率大于对照组,其差异有统计学意义(P0.05)。病理切片结果显示高剂量组伤口愈合程度最高,低剂量组次之,两者都优于对照组。愈合组织相关因子检测表明,伤后第2 d,高剂量上清处理的小鼠伤口组织TGF-β1和Col1a1基因表达增加,明显多于对照组(P0.05),伤后第3 d,实验组VEGF的表达量均高于对照组(P0.05);高剂量组从第3 d开始,IL-1β这一炎症因子表达水平显著低于空白对照组(P0.05)。结论:hUC-MSCs上清凝胶能够提高小鼠皮肤创面愈合的速度。     

重组人表皮生长因子在面部瘢痕修复治疗中的应用

目的:分析重组人表皮生长因子(rhEGF)在面部瘢痕修复治疗中的应用价值。方法:选择2013年3月-2016年2月我院收治的80例面部瘢痕患者作为研究对象,按随机数字表法分为对照组与观察组各40例,两组均应用二氧化碳点阵激光进行面部瘢痕修复治疗,观察组术后加用rh EGF敷于皮肤表面,对照组则采用等渗盐水敷于皮肤表面,比较两组治疗不同时间创面愈合率、创面愈合时间及换药时疼痛情况,测定创面愈合后患者瘢痕面积,并评定创面处理后不同时间患者肉芽组织成熟情况、创面愈合后瘢痕面积及不良反应的发生情况。结果:两组术后7 d、术后14 d创面愈合率均显著高于术后3 d(P0.05),观察组术后不同时间创面愈合率均显著高于对照组(P0.05);观察组创面愈合时间短于对照组,其创面愈合后瘢痕面积小于对照组(P0.05);观察组换药时疼痛程度低于对照组,其轻度疼痛所占比例高于对照组(P0.05);观察组术后7 d、14 d肉芽组织成熟分级均高于对照组(P0.05)。两组均未见炎症全身不良反应。结论:re EGF可促进面部瘢痕患者创面修复,缩短创面愈合时间,缩小瘢痕面积,减轻患者换药疼痛程度,促进肉芽组织成熟,且安全性高。     

湿润烧伤膏联合全蝎软膏治疗糖尿病性皮肤溃疡的疗效观察

目的:评价湿润烧伤膏和全蝎软膏联用治疗糖尿病皮肤溃疡创面愈合的效果并探讨其作用机制。方法:选择Wistar大鼠建立糖尿病皮肤溃疡模型,采用随机数字表法将其分为对照组、模型组、全蝎软膏组、湿润烧伤膏组和联用组,以连续饲喂高脂饲料、腹腔注射链脲佐菌素(STZ)及皮肤损伤法制备糖尿病皮肤溃疡大鼠模型。造模后,分别在创伤处进行药物干预处理,空白组和模型组用PBS处理并计算创面愈合率;采用免疫组化、创面组织超微病理结构观察给药后3 d、7 d、10 d和14 d的创面肉芽组织,western-blot检测Smad4蛋白的表达。结果:糖尿病皮肤溃疡模型组的大鼠体重、血糖与正常组相比有统计学差异,成模率为95.45%;经14 d连续治疗后,各治疗组创面愈合率均高于模型组(P0.05),联用组创面愈合率与对照组水平接近。免疫组化染色结果显示与模型组相比,经药物干预后的创面组织内AGEs和RAGE的表达水平均明显下调(P0.05);电镜观察结果表明联用湿润烧伤膏和全蝎软膏能够促进胞内细胞器恢复正常水平,其改善效果较单独药物干预组效果更显著;Western-blot检测结果表明各治疗组创面组织内Smad 4蛋白水平较模型组显著降低,但联用组中Smad4蛋白水平下调更显著(P0.05)。结论:联合应用湿润烧伤膏和全蝎软膏能够有效促进大鼠糖尿病性皮肤溃疡创面的愈合,可能与调控组织中糖基化终末产物AGEs-RAGE信号通路及下调Smad4蛋白表达水平,抑制炎症反应有关。     

Effects of Foeniculum vulgare essential oil compounds,fenchone and limonene,on experimental wound healing

We investigated the wound healing efficacy of the Foeniculum vulgare compounds, fenchone and limonene, using an excisional cutaneous wound model in rats. An excision wound was made on the back of the rat and fenchone and limonene were applied topically to the wounds once daily, separately or together, for 10 days. Tissue sections from the wounds were evaluated for histopathology. The healing potential was assessed by comparison to an untreated control group and an olive oil treated sham group. We scored wound healing based on epidermal regeneration, granulation tissue thickness and angiogenesis. After day 6, wound contraction with limonene was significantly better than for the control group. Ten days after treatment, a significant increase was observed in wound contraction and re-epithelialization in both fenchone and limonene oil treated groups compared to the sham group. Groups treated with fenchone and with fenchone + limonene scored significantly higher than the control group, but the difference was not statistically significant compared to the olive oil treated group. Our findings support the beneficial effects of fenchone and limonene for augmenting wound healing. The anti-inflammatory and antimicrobial activities of fenchone and limonene oil increased collagen synthesis and decreased the number of inflammatory cells during wound healing and may be useful for treating skin wounds.     

A comparison of the effects of immobilization and continuous passive motion on surgical wound healing in mature rabbits

The purpose of this investigation was to compare the effects of continuous passive motion (CPM) and cast immobilization on postoperative wound healing. Medical parapatellar skin incisions and arthrotomies were performed on both knees of 10 mature New Zealand rabbits. After closure of the incisions, one knee was immobilized in a cast while the other was treated by continuous passive motion for 3 weeks. Six standardized skin specimens (2 mm wide) from each wound were tested to failure and one specimen was examined histologically. With respect to the breaking force, tensile strength, strain at failure, stiffness, and toughness, the wounds in the continuous-passive-motion group were significantly stronger, stiffer, and tougher than those in the cast group. Histologically, the structural organization of the collagen fibers was also superior in the scars treated with continuous passive motion. The results of the present investigation indicate that compared to immobilization, continuous passive motion enhances postoperative wound healing in rabbits.     

Effects of human amniotic membrane grafts combined with marrow mesenchymal stem cells on healing of full-thickness skin defects in rabbits

We have investigated the wound-healing effects of mesenchymal stem cells (MSCs) in combination with human amniotic membrane (HAM) when grafted into full-thickness skin defects of rabbits. Five defects in each of four groups were respectively treated with HAM loaded with autologous MSCs (group A), HAM loaded with allologous MSCs (group B), HAM with injected autologous MSCs (group C), and HAM with injected allologous MSCs (group D). The size of the wounds was calculated for each group at 7, 12, and 15 days after grafting. The wounds were subsequently harvested at 25 days after grafting. Sections stained with hematoxylin and eosin were used to determine the quality of wound healing, as based on the characteristics and amount of granulated tissue in the epidermal and dermal layers. Groups A and B showed the most pronounced effect on wound closure, with statistically significant improvement in wound healing being seen on post-operative days 7, 12, and 15. Although a slight trend toward improved wound healing was seen in group A compared with group B, no statistically significant difference was found at any time point between the two groups. Histological examination of healed wounds from groups A and B showed a thin epidermis with mature differentiation and collagen bundle deposition plus recovered skin appendages in the dermal layer. In contrast, groups C and D showed thickened epidermis with immature epithelial cells and increased fibroblast proliferation with only partially recovered skin appendages in the dermal layer. Thus, the graft of HAM loaded with MSCs played an effective role during the healing of skin defects in rabbits, with no significant difference being observed in wound healing between autologous and allologous MSC transplantation. This study was supported by research funds from Dong-A University.     

EGF and TGF-alpha in wound healing and repair

Wound healing is a localized process which involves inflammation, wound cell migration and mitosis, neovascularization, and regeneration of the extracellular matrix. Recent data suggest the actions of wound cells may be regulated by local production of peptide growth factors which influence wound cells through autocrine and paracrine mechanisms. Two peptide growth factors which may play important roles in normal wound healing in tissues such as skin, cornea, and gastrointestinal tract are the structurally related peptides epidermal growth factor (EGF) and transforming growth factor alpha (TGF-alpha). EGF/TGF-alpha receptors are expressed by many types of cells including skin keratinocytes, fibroblasts, vascular endothelial cells, and epithelial cells of the GI tract. In addition, EGF or TGF-alpha are synthesized by several cells involved in wound healing including platelets, keratinocytes, and activated macrophages. Healing of a variety of wounds in animals and patients was enhanced by treatment with EGF or TGF-alpha. Epidermal regeneration of partial thickness burns on pigs or dermatome wounds on patients was accelerated with topical application of EGF or TGF-alpha, and EGF treatment accelerated healing of gastroduodenal ulcers. EGF also increased tensile strength of skin incisions in rats and corneal incisions in rabbits, cats, and primates. Additional research is needed to better define the roles of EGF, TGF-alpha and their receptor in normal wound healing, to determine if alterations have occurred in the EGF/TGF-alpha system in chronic wounds, and optimize vehicles for effective delivery of peptide growth factors to wounds.     

Cellular mechanisms of skin repair in humans and other mammals

The increased incidence of non-healing skin wounds in developed societies has prompted tremendous research efforts on the complex process known as “wound healing”. Unfortunately, the weak relevance of modern wound healing research to human health continues to be a matter of concern. This review summarizes the current knowledge of the cellular mechanisms that mediate wound closure in the skin of humans and laboratory animals. The author highlights the anatomical singularities of human skin vs. the skin of other mammals commonly used for wound healing research (i.e. as mice, rats, rabbits, and pigs), and discusses the roles of stem cells, myofibroblasts, and the matrix environment in the repair process. The majority of this review focuses on reepithelialization and wound closure. Other aspects of wound healing (e.g. inflammation, fibrous healing) are referred to when relevant to the main topic. This review aims at providing the reader with a clear understanding of the similarities and differences that have been reported over the past 100 years between the healing of human wounds and that of other mammals.     

Effect of pesticides on wound contraction

Agricultural injuries are a complex surgical problem, especially because of frequently extensive skin lesions prone to infection and delayed healing. The aim of the study was to assess the local effect of pesticides, chemical substances widely used in agriculture, on wound healing, especially on wound contraction. Local effects of the combined herbicide composed of atrazine and dual (Primextra) and insecticide alphametrin (Fastac 10% SC) on primary wound healing were assessed in a bioassay performed in 18 New Zealand white rabbits. Relative size of the wound, measured on days 0, 1, 3, 6, 9 and 12 of wounding was analyzed by two-factor analysis of variance with repeat measurements. The activity of the process of restoration was assessed on histopathologic preparations obtained after the last measurement. Results of the study showed the final wound contraction to be smaller and the process of healing slower in the experimental groups of animals. Histopathology revealed defects of epithelialization, phasic delay in healing, infiltration with eosinophilic granulocytes, and decreased density of newly formed collagen. Pesticides were concluded to have adverse local effects on the wound, causing impairment of the mechanisms of healing.     

封闭负压引流对兔糖尿病溃疡创面组织愈合影响的观察

目的:探讨封闭负压引流(VAC)对兔糖尿病溃疡创面组织愈合的影响及其可能机制。方法:采用四氧嘧啶法建立兔糖尿病溃疡模型,设空白对照组和实验组(对照组创面采用常规包扎治疗处理,实验组创面则采用VAC处理),观察和比较两组动物的创面肉眼观、愈合时间,在致伤前、致伤后3 d、7 d、14 d取创面软组织,检测和比较两组动物的创面组织含水量、血流量以及血浆ET-1和NO含量。结果:与对照组比较,实验组动物的创面肿胀及分泌物得到明显控制,创面坏死组织的清除与肉芽组织的生长明显加快,平均愈合时间明显缩短(P0.05);致伤后3 d、7 d和14 d,创面组织含水量与血浆ET-1含量明显下降(P0.05),创面组织血流量与血浆NO含量明显增加(P0.05)。结论:VAC对兔糖尿病溃疡创面组织的愈合可起到积极的促进作用,这可能与其增加血浆NO含量及降低ET-1的含量有关,其具体机制尚有待于进一步的研究。     

局部应用PTD-SOD、SOD对小鼠皮肤创伤的抗氧化应激损伤保护效果及其比较

目的探讨局部应用PTD-SOD、SOD对小鼠皮肤创伤的抗氧化应激损伤保护效果及其差异。方法制备机械性创伤小鼠模型和不同浓度的PTD-SOD(1000、3000、6000 U)及SOD(1000、3000、6000 U)溶液,分别用上述溶液进行治疗,同时设立模型对照组和生理盐水对照组,各组均连续治疗13 d。观察各组创伤愈合情况,记录创伤愈合率和愈合天数;于创伤后第14天取各组小鼠创伤愈合部位皮肤,一部分制成10%组织匀浆液用于检测抗氧化酶(SOD、CAT、GSH-Px)活性及丙二醛(MDA)、羟脯氨酸(Hyp)含量,一部分制成病理组织切片用于皮肤组织学观察。结果①与模型对照组相比,PTD-SOD各组或SOD各组的抗氧化酶活性和Hyp含量显著(P0.05)或极显著(P0.01)升高,MDA含量显著(P0.05)或极显著(P0.01)降低,能显著(P0.05)或极显著(P0.01)提高创伤愈合率、缩短创伤愈合时间;与生理盐水对照组相比,结果类似。②在同等剂量下,从促创伤愈合时间、抗氧化酶活性、MDA含量、Hyp含量等方面比较,PTD-SOD组明显(P0.05)或极明显(P0.01)优于SOD组。③适当剂量的PTD-SOD促创伤愈合效果优于高剂量PTD-SOD的促创伤愈合效果。结论 PTD-SOD或SOD在皮肤创伤治疗中具有良好的抗氧化应激损伤效果,这种保护效果在创伤愈合的早期最显著;同等剂量下,PTD-SOD在促创伤愈合的效果上明显优于SOD。     

A C-type CpG ODN accelerates wound healing via regulating fibroblasts and immune response

Abolished or delayed wound healing is a serious problem in clinical surgery, therefore, the new therapy for wound healing is needed. Synthetic oligodeoxynucleotides containing one or more CpG motifs (CpG ODN) has been reported to activate the immune system and improves skin wound healing. The aim of the present study was to evaluate the role of a new C-type CpG ODN in wound healing. We found that the CpG ODN promoted cell proliferation and collagen I production in human skin fibroblasts cells. Besides, we also investigated the effect of CpG ODN on the activation of immune cells. The macrophages and plasmacytoid dendritic cells (pDCs) were incubated with CpG ODN. CpG ODN activated macrophage and pDCs via regulating TLR9/MyD88/NF-κB pathway and TLR9/MyD88/IRF7 pathway, respectively. To further evaluate the effect of CpG ODN on wound healing in vivo a wound healing model was established in mice. The results showed that CpG ODN treatment accelerated wound healing in mice. CpG ODN increased cytokines secretion in wound skin and elevated the ratio of CD4 ⁺ and CD8 ⁺ T cells in the spleen. Our results showed that CpG ODN accelerated wound healing, which was partly due to the regulation of fibroblasts and immune response. The findings suggested that the CpG ODN might be a proper medicament for the treatment of wound healing.     

Evaluation of persistence and distribution of intra-dermally administered PKH26 labelled goat bone marrow derived mesenchymal stem cells in cutaneous wound healing model

The current study was designed to study the persistence and distribution of caprine bone marrow derived mesenchymal stem cells (cBM-MSCs) when administered intra-dermally in experimentally induced cutaneous wounds in rabbits. MSC’s from goat bone marrow were isolated and their differentiation potential towards adipogenic and osteogenic lineages were assayed in vitro. The isolated cells were phenotypically analysed using flow cytometry for the expression of MSC specific matrix receptors (CD73, CD105 and Stro-1) and absence of hematopoietic lineage markers. Further, these in vitro expanded MSCs were stained with PKH26 lipophilic cell membrane red fluorescent dye and prepared for transplantation into cutaneous wounds created on rabbits. Five, 2 cm linear full thickness skin incisions were created on either side of dorsal midline of New Zealand white rabbits (n = 4). Four wounds in each animal were implanted intra-dermally with PKH26 labelled cBM-MSCs suspended in 500 µl of Phosphate Buffer Saline (PBS). Fifth wound was injected with PBS alone and treated as negative control. The skin samples were collected from respective wounds on 3, 7, 10 and 14 days after the wound creation, and cryosections of 6 µM were made from it. Fluorescent microscopy of these cryosections showed that the PKH26 labelled transplanted cells and their daughter cells demonstrated a diffuse pattern of distribution initially and were later concentrated towards the wound edges and finally appeared to be engrafted with the newly developed skin tissues. The labelled cells were found retained in the wound bed throughout the period of 14 days of experimental study with a gradual decline in their intensity of red fluorescence probably due to the dye dilution as a result of multiple cell division. The retention of transplanted MSCs within the wound bed even after the complete wound healing suggests that in addition to their paracrine actions as already been reported, they may have direct involvement in various stages of intricate wound healing process which needs to be explored further.