一种增生性瘢痕动物模型的建立

目的　建立兔耳瘢痕动物模型 ,观察兔耳腹侧创面在伤后不同时间瘢痕增生的情况。方法　于 32只新西兰白兔的 6 0只兔耳腹面手术切除 2cm× 5cm全层皮肤 ,创面用 1%磺胺嘧啶银冷霜外敷包扎至愈合 ,换药 1次 /周。未作手术的 4只兔耳作对照。 (1)术后连续 12个月观察兔耳创面自然愈合情况。 (2 )用光镜、透射电镜观察兔耳创面瘢痕增生情况。 (3)用计算机图像分析系统测定 1～ 6个月的瘢痕指数。　结果　兔耳创面上皮化后其色泽、厚度和质地均经历从瘢痕形成、成熟到退化的演变过程 ;1～ 2个月的瘢痕指数 2 .2 9± 0 .74较 3～ 4个月 (2 .82± 0 .36 )和 5～ 6个月 (2 .90± 0 .84 )低 (P <0.0 5),其变化与瘢痕增生程度的消长趋势吻合。　结论　兔耳腹面全层皮肤缺损经自然愈合后形成的增生性瘢痕与人体增生性瘢痕相似 ,该模型是研究增生性瘢痕的发生机制及评估其治疗方法的较好的动物模型之一     

放射治疗兔耳增生性瘢痕的实验研究

目的:研究经过医用高能电子线照射兔耳增生性瘢痕实验模型后,观察伤口愈合的情况、瘢痕愈合后的病理改变及肌动蛋白(ACTIN)和血管生长因子(VEGF)表达变化情况。方法:选用日本大耳白兔18只,在每只兔耳腹侧面制作直径6mm的圆形全层皮肤缺损创面10个。将总计360个缺损创面模型随机分为6组,第1组为空白对照组(3只),其余5组为照射组(各3只)。将照射组每只兔耳随机用200cGy、400cGy、600cGy、800cGy、1000cGy的6Mev电子线照射兔耳缺损创面,照射野周围用铅板防护,观察兔耳缺损创面的愈合情况变化及创面愈合后瘢痕组织进展情况。并于致伤一个月后对实验模型取材,进行光镜、电镜及组织学观察。结果:兔耳腹侧面圆形创面缺损,能产生与人类增生性瘢痕类似的增生块。各照射组,缺损创面愈合延迟。总照射剂量相近的情况下,单次不同照射剂量对增生性瘢痕形成的影响有显著性差异。结论:日本大耳白兔可以形成类似人的增生性瘢痕病理改变,可以用作增生性瘢痕研究的实验动物模型。动物实验证明,医用6Mev高能电子线照射治疗是一种有效的治疗增生性瘫痕的方法,总照射剂量相近的情况下,分5次照射、单次剂量400cGy,为最佳照射剂量。     

建立更加稳定和有效的兔耳瘢痕模型

目的：建立更加稳定和有效的兔耳瘢痕模型。方法：选用16只新西兰大耳白兔,分别在兔耳腹侧中段作1cm×1cm的全层皮肤缺损共192个,以形态学、瘢痕增生指数及羟脯氨酸（HPr）的含量变化对创面愈合后形成的增生块,进行动态组织病理学、细胞增殖活性及胶原纤维合成等检测。结果：兔耳腹侧中段创面可产生类似于人类的增生性瘢痕,其发生率为91．5％,增生块最长持续时间可达120多天。结论：采用本实验的模型复制方法,可以得到更加稳定和有效的兔耳增生性瘢痕。     

建立一种兔耳增生性瘢痕的动物模型

目的　建立由动物自身产生的与人增生性瘢痕类似的增生性动物模型。方法　选用2 4只新西兰大耳白兔 ,分别在兔耳腹侧、背侧面作直径 1.5cm的全层皮肤缺损各 14 4个、72个 ,对创面愈合后形成的增生块进行组织病理学、层黏连蛋白 (LN)mRNA及整合素 β1mRNA检测等检查。结果　兔耳腹侧创面可产生类似人增生性瘢痕样的过度增生 ,其发生率为 71% ,以兔耳腹侧面中部为著 ,增生块最长持续时间超过伤口愈合后 15 0d ,而兔耳背侧面的创面增生块发生率不到3 0 % ,且增生块持续时间短 ,为 76d。切片镜下显示 ,增生块的真皮层存在大量成纤维细胞 ,与人增生性瘢痕结构类似。结论　兔耳腹侧面尤其腹侧面的中部可产生类似人增生性瘢痕样病理改变 ,可望成为研究瘢痕的动物模型。     

细菌纤维素对兔耳增生性瘢痕中羟脯氨酸含量的影响

目的：观察细菌纤维素（BC）对兔耳增生性瘢痕的影响。方法：成年新西兰白兔30只,全麻下建立兔耳腹侧增生性瘢痕模型。在术后第21天（创面上皮化）后,根据每只兔耳5个不同瘢痕面随机给予不同处理方式分为5组,分别为3组实验组（贴敷持水性不同的细菌纤维素（BC）膜,A组BC（1：5）、B组BC（1：6）、C组BC（1：8））和2组对照组（贴敷疤痕贴的为阳性对照D组,未贴任何敷料且瘢痕自然生长的为阴性对照E组）。在给予瘢痕面不同处理方式之后的第0天、第14天、第21天、第28天、第42天、第56天分别切取标本行羟脯氨酸（Hpr）含量检测。结果：A、B、C三组瘢痕Hpr含量高于D组但低于E组（P〈0.01）;A、B、C、三组瘢痕Hpr含量分别比较A〉B〉C组（P〈0.05）。结论：兔耳创面愈合后增生性瘢痕贴敷的细菌纤维素抑制了兔耳瘢痕的增生,各组细菌纤维素减轻增生性瘢痕效果比较A组〈B组〈C组。     

A型肉毒毒素对兔耳增生性瘢痕组织中P物质、β1转移生长因子、α平滑肌肌动蛋白的影响

目的探讨A型肉毒毒素（botuliniumtoxintypeA,BTA）对兔耳增生性瘢痕组织中P物质（substanceP,SP）、β1转移生长因子（transforminggrowthfactorbeta一1,TGF—β1）和α平滑肌肌动蛋白（alphasmoothmusleactinA,αSMA）的影响及意义。方法12只日本大耳白兔,体重3kg,建立兔耳增生性瘢痕模型。将兔耳创面分为BTA注射组（I组）和瘢痕组（S组）,每组72个创面。大体观察创面愈合时间和瘢痕增生情况,统计术后14d时的创面愈合率。术后28d时,同法另取6只兔子的兔耳腹面正常皮肤为空白对照组（C组）,收集3组标本。实时定量PCR检测各组标本中SP、TGF-β1和α—SMA的mRNA含量,Western印迹法检测α—SMA的蛋白表达。结果（1）术后14d,Ⅰ组与S组的创面愈合率的差异无统计学意义;（2）1组SP和TGF一β1、α—SMA的mRNA含量较S组显著降低,但仍高于C组（P〈0．05）;（3）蛋白水平上,3组的α—sMA表达两组间比较差异均有统计学意义（P〈0．05）,且S组〉Ⅰ组〉C组。结论BTA注射不延迟创面愈合,并减少了兔耳增生瘢痕中SP、TGF-β1和α—SMA的mRNA表达,为其治疗增生性瘢痕的临床应用提供了一定的理论依据。     

595nm激光对兔耳瘢痕成纤维细胞增殖与凋亡的影响

目的：探讨595nmVbeam激光照射对增生性瘢痕动物模型伤口愈合过程中成纤维细胞增殖与凋亡的影响。方法：成年大耳白兔20只,建立兔耳腹侧面增生性瘢痕模型,对比研究在瘢痕形成过程中595nmVbeam激光照射对兔耳瘢痕成纤维细胞的影响,采用免疫组化方法检测增殖细胞核抗原（PCNA）蛋白表达和细胞凋亡的原位检测。结果：兔耳增生性瘢痕经595nmVbeam激光照射后,按不同时间段取材进行免疫组化染色并与对照组比较,高倍镜下观察结果,显示PCNA蛋白表达明显减弱,细胞凋亡增加。结论：595nmVbeam激光照射可抑制兔耳增生性瘢痕成纤维细胞的增殖过程,诱导细胞凋亡。应用595nmVbeam激光预防和治疗瘢痕是可行的。     

电针抑制兔耳增生性瘢痕形成的作用研究

目的：探究电针刺激在抑制兔耳增生性瘢痕形成过程中的影响。方法：以成年新西兰雄性兔（24只）为实验对象,随机分为电针组、手针组、模型组、空白组,除空白组外其余各组在兔耳腹侧面造成创面以形成瘢痕组织,然后根据组别分别在血海与翳风穴给予不同的刺激,比较各组兔耳增生性瘢痕形成情况,测定增生性瘢痕的瘢痕增生指数、各样品组织中羟脯氨酸的含量及胶原纤维的排列。结果：电针治疗组的瘢痕增生指数与其他各组存在明显差异（P〈0．05）,HE染色在光镜下可见胶原纤维组织排列整齐度的增加及胶原纤维组织含量的降低。结论：电针可以抑制兔耳增生性瘢痕形成。     

A型肉毒毒素局部应用对兔耳增生性瘢痕创面愈合和瘢痕增生的影响

目的 研究A型肉毒毒素对兔耳增生性瘢痕组织的影响.方法 8只日本大耳白兔,体重3 kg,建立兔耳增生性瘢痕模型.将兔耳创面分为A型肉毒毒素治疗组(T组)和瘢痕组(S组),每组48个创面.大体观察创面愈合时间和瘢痕增生情况.术后28 d,同法另取4只兔子的兔耳腹面健康皮肤为空白组(B组),收集标本.测量S、T组标本HE切片的瘢痕增生指数HI,流式细胞仪分析2组标本中成纤维细胞的细胞周期,western-blot检测S、T、B组标本中Ⅰ、Ⅲ型胶原的蛋白表达.结果 ①T组标本的瘢痕增生指数HI较S组显著降低,P<0.01;②蛋白水平上,T组的胶原Ⅰ、Ⅲ蛋白表达和胶原Ⅰ/Ⅲ比值均较s组显著降低,P<0.01;③S组分布于G2-M期和S期的成纤维细胞较T组显著增多,而静止期G0-G1的细胞则显著减少,P<0.05.结论 A型肉毒毒素局部应用能抑制兔耳增生瘢痕的形成.抑制成纤维细胞的增殖活性,减少瘢痕组织中Ⅰ、Ⅲ型胶原的合成,降低胶原Ⅰ/Ⅲ比值,为其治疗增生性瘢痕的临床应用提供了一定的理论依据.     

高压氧对兔耳创面模型早期瘢痕组织形成的影响

目的 通过观察高压氧对兔耳创面愈合及瘢痕形成的影响,以探讨在临床中应用高压氧防治早期瘢痕的可行性.方法 选取新西兰白兔16只建立兔耳增生性瘢痕模型,每只兔左耳4个创面,右耳4个创面,共128个,随机分为高压氧组与对照组2组,每组8只,64个创面.高压氧组术后立即开始高压氧处理,2个大气压,吸氧60 min,每日1次,疗程以创面愈合为准.期间观察记录创面愈合情况以及兔耳瘢痕大小、厚度、颜色、硬度.待创面全部愈合后,切取创面进行HE染色,Masson染色和苦味酸天狼星红染色,行病理学观察、检测及分析.结果 高压氧组愈合时间为(16.7±1.8)d;对照组为(20.2±2.3)d,差异有统计学意义(P＜0.05).高压氧组瘢痕增生发生率较对照组低,实验组发生率为(38/64,59.4％),对照组发生率为(52/64,81.2％),差异有统计学意义(P＜0.05).光镜下观察,高压氧组真皮层较对照组薄,成纤维细胞数量较少,胶原较疏松,排列较整齐,胶原结节和漩涡状结构少.瘢痕增生指数,高压氧组为3.48±0.94,对照组为4.65 ±0.76,差异有统计学意义(P＜0.01).成纤维细胞密度,高压氧组为186.5±27.3,对照组为246±41.6,差异有统计学意义(P＜0.05).胶原纤维面密度,高压氧组为(31.42±5.36)％,对照组为(43.62±7.36)％,差异有统计学意义(P＜0.05).Ⅰ型和Ⅲ型胶原含量,高压氧组分别为(71.42±5.36)％和(28.58±5.36)％,对照组为(62.46±7.32)％和(37.54±7.32)％,差异有统计学意义(P＜0.05).Ⅰ型和Ⅲ型胶原比例,高压氧组为2.499,对照组为1.664,高压氧组比例更为接近正常皮肤Ⅰ型和Ⅲ型胶原约4∶1的比例.结论 高压氧可促进创面愈合,并对兔耳早期增生性瘢痕有较明显的抑制作用.     

Inhibition of prolyl 4-hydroxylase reduces scar hypertrophy in a rabbit model of cutaneous scarring

Hypertrophic scars result from excessive collagen deposition at sights of healing dermal wounds and can be functionally and cosmetically problematic. Pharmacological regulation of collagen synthesis and deposition is a direct approach to the control of scar tissue formation. We tested the ability of the phenanthrolinone derivative FG-1648 (in 0.5% Carbopol 971 PNF gel, pH 6.5), a prolyl 4-hydroxylase inhibitor, to reduce hypertrophic scar formation in a rabbit ear hypertrophic scar model. New Zealand White rabbits were divided into two treatment groups (n = 12 wounds per group with an equal number of controls): low-dose group: 0.5% FG-1648; high-dose group: 1% FG-1648. Left ears were used for treatment and right ear for control. Four 7-mm dermal ulcer wounds were made on each ear. The inhibitor was topically applied to the wound at the time of wounding and once daily up to postoperative day 7. Wounds were harvested at postoperative day 28 and scar hypertrophy quantified by measurement of the scar elevation index. All wounds showed complete healing. Treatment of wounds with 1% prolyl 4-hydroxylase inhibitor decreased the scar elevation index by 26% compared to control wounds (p < 0.01). Wounds treated with 0.5% FG-1648 inhibitor showed no difference in scar elevation compared to control wounds. These results suggest that inhibition of prolyl 4-hydroxylase may be a suitable agent for topical treatment for the prevention of hypertrophic scar tissue.     

The temporal effects of anti-TGF-beta1, 2, and 3 monoclonal antibody on wound healing and hypertrophic scar formation

BACKGROUND: A number of studies have implicated transforming growth factor (TGF)-beta1, 2, and 3 (TGF-beta) in wound healing and hypertrophic scarring. We propose that TGF-beta has a temporal effect on these processes. To test this hypothesis, we applied anti-TGF beta1, 2, and 3 monoclonal antibody topically to our dermal ulcer model in the rabbit ear. STUDY DESIGN: Rabbit ear wounds were treated intradermally with anti-TGF-beta1, 2, and 3 antibody at early, middle, and late time points. Treated and untreated control wounds were harvested at various time points and examined histologically to quantify wound healing and scar hypertrophy. Real-time polymerase chain reaction was performed to determine TGF-beta mRNA expression in the treated and control wounds. RESULTS: The early treatment group demonstrated decreased new epithelium and granulation tissue (p < 0.05 versus controls). Scars harvested on days 28 and 40 displayed no difference in scar hypertrophy. Both the middle and late treatment groups demonstrated a significant decrease in scar hypertrophy (p < 0.05). CONCLUSIONS: Treated wounds from the early treatment group displayed delayed wound healing, with no reduction in scar hypertrophy. Later treatment of wounds with the same antibody, beginning 7 days after wounding, resulted in a reduction in scar hypertrophy. These results support our hypothesis and clearly demonstrate that TGF-beta1, 2, and 3 have differential temporal effects during the wound-healing process, and are important for optimal wound healing in the first week after wounding; beyond 1 week, TGF-beta1, 2, and 3 play a critical role in hypertrophic scar formation.     

Inhibition of procollagen C-proteinase reduces scar hypertrophy in a rabbit model of cutaneous scarring

Hypertrophic scarring, which results from excessive collagen deposition at sites of dermal wound repair, can be functionally and cosmetically debilitating to the surgical patient. Pharmacological regulation of collagen synthesis and deposition is a direct approach to the control of scar tissue formation. One of the key steps in collagen stabilization is the cleavage of the C-terminal propeptide from the precursor molecule to form collagen fibrils, a reaction catalyzed by procollagen C-proteinase (PCP). We tested the ability of a PCP inhibitor to reduce hypertrophic scar formation in a rabbit ear model. After the placement of four, 7-mm dermal wounds on each ear, New Zealand white rabbits received PCP inhibitor subcutaneously in the left ear at four time points postwounding: days 7, 9, 11, 13 (early treatment; n=20 wounds) or days 11, 13, 15, 17 (late treatment; n=20 wounds). The right ear of each animal served as a control (vehicle alone). Wounds were harvested on postoperative day 28 and scar hypertrophy quantified by measurement of the scar elevation index. Early treatment of wounds with PCP inhibitor did not reduce scar formation compared with controls (p>0.05). However, late treatment resulted in a statistically significant reduction in the scar elevation index (p<0.01). Our results point not only to the potential use of PCP inhibitors to mitigate hypertrophic scarring but also to the temporal importance of drug delivery for antiscarring therapy.     

他克莫司预防兔耳瘢痕增生的实验研究

目的：研究他克莫司对兔耳瘢痕增生的影响。方法：选10只新西兰白兔雌雄各半,按本研究组建立的改良方法制作兔耳瘢痕模型,左耳为空白对照组涂凡士林软膏,右耳为实验组涂他克莫司软膏。伤后14天、21天、28天、35天及49天采集标本,行苏木精-伊红（HE）及Masson三色法染色,统计成纤维细胞密度,实时定量PCR（Real-time PCR）检测细胞外基质成分Ⅰ型胶原（collagen Ⅰ;ColI）和纤维连接蛋白（fibronectin;Fn）,CD4＋辅助性T细胞-2（Th2）产生的重要纤维化基因IL-4及参与T细胞早期活化的重要基因巨噬细胞集落刺激因子（macrophage colony stimulating factor;M-CSF）和肿瘤坏死因子-α（tumor necrosis factorα;TNF-α）的表达。结果：HE及Masson三色法染色可见实验组较对照组胶原沉积明显减少,PCR结果可见ColI、Fn、IL-4、M-CSF和TNF-α在实验组中的表达较对照组在各时间点均减少。结论：应用他克莫司可通过下调IL-4、M-CSF和TNF-α的表达来抑制兔耳瘢痕增生。     

15-脱氧-△^12,14-前列腺素J2对兔耳增生性瘢痕的作用

目的探讨γ过氧化物酶体增殖物激活受体（peroxisome proliferator activated receptor-7,PPAR-γ）的配体15-脱氧-△^12,14-前列腺素J2（15-deoxy-△^12,14-prostagliandxinJ2,15d—PGJ2）对兔耳增生性瘢痕I型胶原、结缔组织生长因子（connective tissue growth factor,CTGF）、α平滑肌肌动蛋白（a—smooth muscle actin,α—SMA）表达的影响,探讨15d—PGJ2防治增生性瘢痕的可能性。方法选取新西兰大白兔18只,在兔耳腹侧面制作2cm×3cm全层皮肤缺损创面,每耳2个,共计72个,建立兔耳增生性瘢痕动物模型,随机分为2组,一组为实验组,另一组为对照组,分别用15d—PGJ2和生理盐水行瘢痕内注射,1次／d,共7次。停药后第7、14、21天两组同时取材;每组每次切取12个组织块。应用免疫组织化学检测I型胶原、CTGF和α—SMA的表达。结果各组兔耳腹侧创面愈合后均不同程度出现类似人增生性瘢痕的组织块。与对照组相比,15dPGJ2注射后瘢痕体积缩小,变软变平,色泽轻度变浅。在各个时间点15d—PGJ2组I型胶原、CTGF和α-SMA的表达均较对照组低,且差异有统计学意义（P〈0．05）。结论PPAR-γ的配体15d—PGJ2可降低瘢痕内I型胶原、CTGF和α—SMA的含量,引起瘢痕萎缩,有一定防治瘢痕的作用,可能为临床治疗增生性瘢痕提供一条新的途径。     

Basic fibroblast growth factor (bFGF) alleviates the scar of the rabbit ear model in wound healing

Studies suggest a possible antiscarring effect of basic fibroblast growth factor (bFGF) during wound healing. However, little is known about the precise pathological mechanisms of bFGF. In particular, there is only limited information available about the mechanism of exogenous administration of bFGF to scar formation. To investigate the effect of bFGF on the hypertrophic scar in the rabbit ear model and to clarify the mechanisms of bFGF on treatment for scar in wound healing, the rabbit ear model of wound healing was created and treated topically with bFGF once daily for 3 months; then we examined the changes of macroscopic and histopathological characteristics of scars and the expression of collagen and collagenase-1 (matrix metalloproteinase-1). The results of macroscopic and histologic characteristics revealed a significant difference between scars treated with bFGF and control scars. The expression of collagen in the scars treated with bFGF was decreased, as compared with the scars treated with saline. Further study revealed that bFGF could remarkably enhance expression of matrix metalloproteinase-1. bFGF could improve the quality of wound healing and remarkably alleviate the scar in the rabbit ear model in wound healing, which suggests that bFGF exerted a net negative effecton scar formation in wound healing. The evidence should contribute to a better understanding of the biological activities of bFGF during hypertrophic scar formation.     

Improvement of hypertrophic scarring by using topical anti‐fibrogenic/anti‐inflammatory factors in a rabbit ear model

This study investigates the scar‐reducing efficacy of topical application of stratifin and acetylsalicylic acid (ASA) in a rabbit ear model. A total of five New Zealand white rabbits with four wounds per ear were examined. Either recombinant stratifin (0.002%) or ASA (0.5%) incorporated in carboxymethyl cellulose gel was topically applied on each wound at postwounding Day 5. Scars were harvested at postwounding Day 28 for histological analysis. The wounds treated with stratifin and ASA showed 82 and 73% reduction in scar volume, respectively, compared with that of untreated controls. A reduction of 57 and 41% in total tissue cellularity along with 79 and 91% reduction in infiltrated CD3⁺ T cells were observed in response to treatment with stratifin and ASA, respectively, compared with those of untreated controls. Wounds treated with stratifin showed a 2.8‐fold increase in matrix metalloproteinase‐1 expression, which resulted in a 48% decrease in collagen density compared with those of untreated controls. Qualitative wound assessment showed a reduced hypertrophic scarring in stratifin and ASA‐treated wounds when compared with the controls. This study showed that topical application of either stratifin or ASA‐impregnated carboxymethyl cellulose gel reduced hypertrophic scar formation following dermal injuries in a rabbit ear fibrotic model.     

The effect of the angiogenesis inhibitor, angiostatin, on hypertrophic scarring

Introduction: Hypertrophic scarring is commonly seen by plastic surgeons in China. Since the etiology of hypertrophic scarring is still unknown, the only reliable treatment is surgical excision. To understand if angiogenesis plays an important role in the formation of hypertrophic scars, we investigated the effect of angiostatin, a potent angiogenesis inhibitor, on hypertrophic scar formation. Our hypothesis is that angiogenesis is required for increased scar formation and angiogenesis inhibition may be one of the methods that can be used to prevent the formation of hypertrophic scars. Methods: We have developed a reliable model in rabbits that results in hypertrophic scarring by creating a 6mm x 6mm full thickness skin wound on both ears. The cDNA for angiostatin is cloned into the pcDNA 3.1 mammalian expression vector. After the wounds re-epithelialized but prior to excessive scarring, the angiostatin expression vector was injected with Lipofectin 2000 once every two days. The expression of angiostatin was confirmed by RT-PCR. The scar tissue was harvested 14 days after injection and processed for histology and total protein. Histology was examined with routine stains, the amount of collagen deposition in the scar tissue was detected by proline assay, and TGF-β1 and VEGF expression was detected by western blot. Results: Compared to the control injection scar, the injection of angiostatin led to a much more normal-looking of scar in the rabbit ear. The proline assay demonstrated that the injection of the angiostatin expression vector resulted in much less collagen in the scar tissue. Western blot analysis showed there was less TGF-β1 and VEGF protein expression in the treated ear compared to the control. Conclusion: The introduction of a vector over-expression angiostatin can result in the decreased formation of hypertrophic scars in a rabbit ear model. This is corroborated by evidence of decreased collagen deposition, the primary extracellular matrix component of scars. In addition, we demonstrate the decreased expression of τηε pro-fibrosis growth factor, TGF-1, and the potent angiogenic factor, VEGF. These data suggest that angiogenesis inhibitors may have a potential role in the treatment of hypertrophic scarring.