黄芪注射液对体外血管新生的影响

背景：血管新生受生长因子的影响,黄芪可与血管内皮生长因子具有协同促血管新生的功效,但机制尚不明确。 目的：通过与单一血管内皮生长因子干预比较,观察中药黄芪对体外血管新生的作用机制。 方法：将黄芪注射液及血管内皮生长因子作用于SD大鼠胸主动脉内皮细胞,应用细胞增殖、细胞迁移、小管形成实验观察黄芪注射液对体外血管新生的促进作用,用Western blot实验检测血管内皮生长因子的表达。 结果与结论：黄芪能明显促进大鼠胸主动脉内皮细胞的增殖(P < 0.01),迁移的细胞数增加(P < 0.01),胸主动脉内皮细胞的小管形成数增加(P < 0.01),并明显促进内皮细胞血管内皮生长因子的表达(P < 0.01)。说明黄芪能明显促进内皮细胞增殖、细胞迁移、小管形成,具有显著的促进体外血管新生作用,其机制可能是通过增加血管内皮生长因子的表达而实现的。     

黄芪、脉络宁注射液载入修饰胶原对鸡胚尿囊膜血管新生的协同促进作用

背景:课题组先期研究发现黄芪载入修饰后胶原可以促进血管新生,与生长因子载入疗效相当,运用中医理论中具有协同作用的中药合用是否能进一步提高疗效尚不清楚。目的:探查黄芪、脉络宁载入修饰后胶原促鸡胚尿囊膜血管新生及长入胶原的疗效,并证明黄芪与脉络宁是否有协同作用。方法:实验分空白组、控制组(单纯胶原)、黄芪组(黄芪注射液1mL载入胶原)、脉络宁组(脉络宁注射液1mL载入胶原)、黄芪+脉络宁组(黄芪注射液及脉络宁注射液各0.5mL载入胶原),各组植入鸡胚尿囊膜孵化7d后取出,测定鸡胚尿囊膜内微血管数、各组胶原内微血管数、血红蛋白含量、rhVEGF165阳性细胞数。结果与结论:各实验组鸡胚尿囊膜内血管呈轮辐状生长及鸡胚尿囊膜包裹标本率高于空白组与控制组,鸡胚尿囊膜内微血管数、胶原内微血管数、血红蛋白含量、rhVEGF165阳性细胞数均高于控制组,差异有显著性意义(P0.01);其中黄芪+脉络宁组又高于黄芪组与脉络宁组,差异有显著性意义(P0.05)。提示黄芪、脉络宁载入胶原后可以促进鸡胚尿囊膜内血管新生并刺激血管长入胶原内,黄芪与脉络宁合用具有协同作用,机制之一为刺激血管内皮细胞血管内皮生长因子的表达。     

血管内皮生长因子促多囊肾大鼠胆管上皮细胞活力及胆管囊性扩张的机制研究

目的:探讨血管内皮生长因子(vascular endothelial growth factor, VEGF)促进多囊肾(polycystic kidney, PCK)大鼠胆管上皮细胞活力及胆管囊性扩张的机制。方法:免疫组织化学染色法检测正常和PCK大鼠肝组织中VEGF (n=6)和CD31 (n=10)的表达情况。RT-qPCR法和酶联免疫吸附实验分别检测胆管上皮细胞和培养上清液中的VEGF表达水平。WST-1比色法检测VEGF对大鼠胆管上皮细胞活力和胆管上皮细胞上清液对内皮细胞活力的影响。细胞迁移实验和管腔形成实验检测胆管上皮细胞上清液对大鼠血管内皮细胞迁移和管腔形成能力的影响。结果:免疫组织化学染色结果表明,VEGF在PCK大鼠的胆管上皮细胞中呈高表达;肝汇管区新生微血管数量明显多于正常大鼠(P0.01);RT-qPCR法和酶联免疫吸附法检测结果表明,PCK大鼠胆管上皮细胞中VEGF mRNA和蛋白表达显著高于正常大鼠(P0.01);WST-1结果显示,VEGF可增强PCK大鼠胆管上皮细胞活力(P0.01);PCK大鼠胆管上皮细胞培养上清液能提高内皮细胞活力(P0.01);VEGF siRNA和VEGF受体抑制剂可降低胆管上皮细胞活力(P0.01);细胞迁移实验和管腔形成实验结果表明,PCK大鼠胆管上皮细胞培养上清液可提高内皮细胞迁移能力和管腔形成能力(P0.01)。结论:PCK大鼠的胆管囊性扩张与胆管上皮细胞过度分泌VEGF存在联系。     

miR-18a对人主动脉内皮细胞血管生成能力的影响

目的: 观察miR-18a对人主动脉内皮细胞血管生成能力的影响。方法: 分别将10 nmol/L miR-18a mimics和20 nmol/L miR-18a inhibitor转染至人主动脉内皮细胞,qRT-PCR法检测miR-18a表达情况并观察内皮细胞的迁移、黏附和管腔形成能力。结果: 转染48 h后,miR-18a mimics组miR-18a表达为对照组的608倍(P<0.05);miR-18a inhibitor组miR-18a表达降低至 对照组的31%(P<0.05)。与对照组相比,miR-18a mimics转染后迁移至Transwell小室下层的内皮细胞数目和毛细血管管腔形成数目分别减少60%和52%(P<0.01);而miR-18a inhibitor转染后分别增加100%(P<0.05)和84%(P<0.01),细胞黏附能力增加43%(P<0.05)。结论: miR-18a的表达水平与人主动脉内皮细胞的血管生成能力相关,可能成为血管性疾病治疗的分子靶点。     

胰岛素对牛胸主动脉内皮细胞血管内皮生长因子及其受体表达的影响

目的:评价胰岛素对培养的牛胸主动脉内皮细胞血管内皮生长因子(VEGF)及其受体表达的影响。方法: 取新生的小牛胸主动脉,做血管内皮细胞原代及传代培养,取4-6代培养细胞分组,应用不同浓度的胰岛素(30 mU/L、300 mU/L、3 000 mU/L)干预培养过程,48 h后应用免疫组化法测定内皮细胞VEGF及其受体(flt-1、flk-1/KDR)的表达水平。结果: 低浓度胰岛素组(30 mU/L、300 mU/L)内皮细胞VEGF表达明显高于不用胰岛素组(P<0.01);高浓度组(3 000 mU/L)内皮细胞VEGF表达明显低于不用胰岛素组(P＜0.05);各组内皮细胞VEGF受体(flt-1及flk-1/KDR)的表达无明显差异(P＞0.05)。结论: 低浓度胰岛素促进小牛主动脉血管内皮细胞VEGF表达;高浓度胰岛素可抑制血管内皮细胞VEGF表达;胰岛素对小牛主动脉血管内皮细胞VEGF受体(flt-1、flk-1/KDR)的表达无直接影响。     

基于VEGFR2/Src/FAK通路探讨葫芦素D抗血管新生机制

目的探讨葫芦素D对VEGF诱导的血管新生的作用及其机制。方法鸡胚绒毛尿囊膜血管新生实验、大鼠胸主动脉血管内皮迁出与人血管内皮细胞划痕实验检测葫芦素D对VEGF诱导的血管新生和内皮细胞迁移的作用,Western blot技术检测葫芦素D对VEGF诱导的VEGFR2及其下游的Src、FAK磷酸化水平的影响。结果葫芦素D对VEGF诱导的鸡绒毛尿囊膜血管新生具有明显的抑制作用,并能抑制VEGF诱导的大鼠胸主动脉环模型和划痕实验中血管内皮迁移。葫芦素D能够抑制VEGF刺激的VEGFR2、Src、FAK磷酸化。结论葫芦素D具有抑制VEGF诱导的血管新生作用,其机制可能与抑制VEGFR2及其下游的细胞信号通路蛋白活化有关。     

尾加压素Ⅱ对大鼠胸主动脉球囊损伤后血管重塑的作用

目的： 探讨尾加压素Ⅱ(UII)在血管损伤后重塑过程中的作用。方法: 建立大鼠胸主动脉球囊拉伤模型，随机分为4组（n=5）,分别为假拉伤组、拉伤组、UII组（胸主动脉球囊拉伤并持续泵入UII 1.0 nmol·kg-1·h-1）和urantide组( 胸主动脉球囊拉伤并持续泵入urantide 10 nmol·kg-1·h-1)。于第21 d取胸主动脉，分别检测血管形态改变、UII表达、平滑肌细胞增殖和胶原表达。结果: ①术后第21 dUII组收缩压高于拉伤组［（140.0±10.0) mmHg vs (132.0±3.4) mmHg, P>0.05］,明显高于urantide 组［（140.0±10.0) mmHg vs (128.0±2.4) mmHg, P<0.05］。②胸主动脉球囊损伤后,损伤血管局部UII表达增强。③同拉伤组比, UII组进一步促进了内膜的增生,管腔面积狭窄率明显增加(0.13±0.05 vs 0.07±0.02, P<0.05);细胞增殖指数明显增加(0.74±0.16 vs 0.40±0.11,P<0.01);胶原表达也明显增加(以IOD计量,318±127 vs 78±26, P<0.01)。④同拉伤组比,urantide组管腔面积狭窄率没有减轻(0.09±0.03 vs 0.07±0.02, P>0.05);细胞增殖指数明显增加(0.73±0.15 vs 0.40±0.11, P<0.01);胶原表达增多但无统计学意义(以IOD计量,200±79 vs 78±26, P>0.05)。结论: 大鼠胸主动脉损伤后局部UII表达增强；外源性UII促进新生内膜平滑肌细胞增殖和胶原表达，加重了损伤血管的狭窄，提示UII参与了损伤后修复的过程；10 nmol·kg-1·h-1urantide不能抑制损伤后血管重塑的进程, 拮抗UII的机制尚有待进一步探讨。     

黄芪多糖胶原干预周围组织中核因子κB与血管内皮细胞生长因子表达而 促进毛细血管新生**

背景：补气生血类中药具有与生长因子促血管生成作用相近的功效。 目的：观察黄芪多糖胶原促血管新生的疗效,及其对血管内皮细胞生长因子基因表达的核因子κB通路的影响。 方法：采用大鼠背部皮下植入模型,分别将黄芪多糖胶原和空白胶原植入大鼠背部两侧,于植入后3,7,14,21 d处死大鼠,取胶原周围肉芽组织进行检测。 结果与结论：造模后3 d时,大鼠肉芽组织中微血管数开始增加,7~14 d时达到峰值,之后下降。在造模后3,7,14 d,植入黄芪多糖胶原的大鼠周围肉芽组织中毛细血管数、血管内皮细胞生长因子mRNA及核因子κB蛋白的表达均显著高于植入空白胶原的大鼠(P < 0.01),且核因子κB蛋白的表达早于毛细血管新生与血管内皮细胞生长因子mRNA的表达。说明黄芪多糖胶原促血管新生作用有可能是通过活化核因子κB信号通路而上调血管内皮细胞生长因子mRNA表达实现的。     

转录因子Bach1对人微血管内皮细胞的作用研究

 目的:研究转录因子Bach1对人微血管内皮细胞功能的影响。方法: 利用小干扰RNA（small interfering RNA,siRNA）细胞转染技术下调内皮细胞Bach1表达;用Matrigel管腔形成实验检测内皮细胞体外血管新生的能力;用Transwell小室法检测细胞迁移;用CCK-8法测定细胞增殖;用实时荧光定量PCR、Western blotting和ELISA法检测细胞中血红素氧合酶1（heme oxygenase 1,HO-1）和血管内皮细胞生长因子（vascular endothelial growth factor, VEGF）mRNA 和蛋白的表达情况;用转染报告基因的方法检测VEGF基因的转录活性。结果: 下调内皮细胞Bach1表达明显促进人微血管内皮细胞迁移和管腔形成能力,对内皮细胞增殖能力无明显影响;抑制Bach1表达促进内皮细胞HO-1 mRNA 和蛋白的表达,增加VEGF 转录活性及mRNA和蛋白的表达。结论: 抑制转录因子Bach1表达可增加内皮细胞HO-1和VEGF的表达,促进人微血管内皮细胞迁移和管腔形成,提示Bach1是负性调控血管新生的因子。     

VEGF高表达的胶质瘤细胞对体外共培养微血管内皮细胞的作用

目的以VEGF阴性表达的正常鼠肝细胞系BRL3A为对照 ,研究VEGF高表达的恶性胶质瘤细胞系C6对体外共培养的肺微血管内皮细胞的作用。方法建立体外C6 ,BRL3A与微血管内皮细胞共培养方法 ,观察不同培养体系中内皮细胞活体形态的改变、毛细血管管腔样结构形成的数量、用生长曲线和流式细胞仪观察内皮细胞的增殖状况 ;利用免疫细胞化学的方法检测共培养后的内皮细胞上和血管新生有关的生长因子和受体的表达变化。结果发现与胶质瘤细胞C6共培养时 ,可引起内皮细胞的增殖速度加快 ,细胞周期中S期和G2-M期百分率与对照组相比明显增加(P<0.05),内皮细胞呈现大量的毛细血管管腔样结构 ;而与BRL3A共培养内皮细胞呈现相对静止的状态(P<0.01) ,未观察到形态学的明显变化。免疫细胞化学结果显示与C6共培养的内皮细胞Flk_1、Flt_1蛋白表达增加(P<0.05) ,而与BRL3A共培养的内皮细胞Flk_1、Flt_1蛋白表达下降(P<0.01)。结论胶质瘤细胞C6可使共培养的肺微血管内皮细胞转化为血管新生活跃的状态 ,其可能原因为C6合成分泌的VEGF上调Flk_1、Flt_1的表达。     

The effect of cross-linking of collagen matrices on their angiogenic capability

The poor vascularization rate of matrices following cell invasion is considered to be one of the main shortcomings of scaffolds used in tissue engineering. In the past decade much effort has been directed towards enhancing the angiogenic potential of biomaterials. A great many studies have appeared reporting about enhancement of vascularization by immobilizing angiogenic factors, such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor-2 (FGF-2). We have also tried to achieve this goal by modifying collagen matrices by covalent incorporation of heparin into the matrices and loading them with VEGF. We and others have observed that loading angiogenic factors to heparinized materials markedly increases angiogenic capacity. In the present paper we also investigated the angiogenic properties of collagen matrices which were only cross-linked, i.e. in the absence of heparin. The angiogenic capacity of the modified matrices was evaluated using the chorioallantoic membrane assay. Differences in angiogenic potential were deduced from macroscopic and microscopic analyses of the chorioallantoic membrane, as well as from dry weight changes. Cross-linked only matrices and matrices both cross-linked and heparinized appeared to show a significantly larger angiogenic potential than unmodified matrices. As previously observed, loading VEGF to these matrices further stepped up angiogenic potential. Quite surprisingly, cross-linking had a substantial impact on angiogenic potential. In terms of magnitude, this effect was similar to the effect of loading VEGF to heparinized matrices. Both modification procedures resulted in an increase of average pore size within the collagen matrices, and this observation may explain the more rapid invasion of mouse fibroblasts into cross-linked and heparinized matrices. Form changes of the implants were also monitored during the in vivo contacts: cross-linked and heparinized matrices showed far better resistance against contraction, as compared to unmodified matrices. Results from the chorioallantoic membrane assay experiments were compared with data obtained from rat model experiments, which confirmed the results from the chorioallantoic membrane assay. This relatively simple assay was again shown to be extremely helpful in evaluating and predicting the angiogenic capabilities of biomaterials for use in tissue engineering and wound healing.     

Modulation of angiogenic potential of collagen matrices by covalent incorporation of heparin and loading with vascular endothelial growth factor

One of the prominent shortcomings of matrices for tissue engineering is their poor ability to support angiogenesis. We report here on experiments to enhance the angiogenic properties of collagen matrices. Our aim is to achieve this goal by covalently incorporating heparin into collagen matrices and by physically immobilizing angiogenic vascular endothelial growth factor (VEGF) to the heparin. The immobilization of heparin was performed with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS). Carboxyl groups on the heparin are activated to succinimidyl esters, which react with amino functions on the collagen to zero length cross-links. This modification leads--in addition to the incorporation of heparin--to gross changes in in vitro degradation behavior and water-binding capacity. As a first approach to testing angiogenic capabilities, endothelial cells were exposed to nonmodified and heparinized collagen matrices. This exposure leads to an increase in endothelial cell proliferation. The increase can be further enhanced by loading the (heparinized) collagen matrices with VEGF. Evaluation of the angiogenic potential of heparinized matrices was further investigated by exposing them to the chorioallantoic membrane of chicken embryos and to the subcutaneous tissue of rats. Both approaches show that heparinized matrices have substantially increased angiogenic potential. In particular, the loading of heparinized matrices with VEGF invokes a further increase in angiogenic potential. It is apparent that the physical binding of VEGF to heparin allows for a release that is beneficial to angiogenesis. By varying the heparin and EDC/NHS concentrations during the modification process and by varying the loading with VEGF, the angiogenic potential as well as the degradation behavior can be adapted to obtain matrices that fulfill specific angiogenic requirements in the field of tissue engineering.     

Evaluation of RGD modification on collagen matrix

OBJECTIVE: To observe the changes during the process of modificating collagen with Arg-Gly-Asp (RGD) peptide, a series experiments were designed.Methods: The 3D porous collagen matrices modified with RGD peptide were constructed by lyophilization. The modified and unmodified matrices were characterized by Scanning Electron Microscopy (SEM) and Electron Spectroscopy for Chemical Analysis (ESCA). Fibroblasts were used to evaluate the cell compatibility of the matrices.Results: In terms of cell growth, the cells attached much better on the modified matrix than on the unmodified one. Compare to the unmodified matrices, the polar groups on the modified matrix increased.Conclusions: The introducing of specific RGD receptor-mediated adhesion site on matrices obviously enhanced the cells adhesion on collagen matrices.     

The impact of proteinase-induced matrix degradation on the release of VEGF from heparinized collagen matrices

The in vivo application of engineered matrices in human wound healing processes is often hampered by the slow rate of vascularization. Therefore much research is directed towards enhancing the angiogenic properties of such matrices. One approach for enhancing the vascularization is the incorporation of angiogenic growth factors. Recently, we and others have reported on immobilizing such factors into collagen matrices either by covalent attachment or by physical binding to covalently incorporated heparin. Especially the latter procedure has been shown to lead to substantial increase rates in vascularization in in vivo experiments. The increases have been proposed to depend on the sustained release of the incorporated angiogenic growth factors from the heparinized collagen matrices. In this paper, we report on investigations to study the release of vascular endothelial growth factor (VEGF) from collagen matrices under conditions which mimic potential in vivo situations. Relevant proteinase concentrations were deduced from in vitro experiments in which we evaluated the secretion of selected matrix metalloproteinases from fibroblasts in contact with collagen. The release of VEGF from non-modified, cross-linked and heparinized collagen matrices in the absence and in the presence of varying concentrations of proteinases was then determined by ELISA and liquid scintillation counting. The release behaviour appears to be controlled by both the presence of heparin and the levels of proteinases applied. Experiments with matrices containing radioactively labelled heparin suggest that VEGF release results from the consecutive and simultaneous release of three species of VEGF molecules that differ in their binding affinities to the differently modified collagen matrices. The species binding specifically to heparin most likely accounts for the previously observed increases in angiogenic potential between loading VEGF to non-heparinized and heparinized collagen matrices.     

A novel dermal substitute based on biofunctionalized electrospun PCL nanofibrous matrix

In this study, nanofibrous matrices of polycaprolactone (PCL) and PCL/collagen with immobilized epidermal growth factor (EGF) were successfully fabricated by electrospinning for the purpose of damaged skin regeneration. Nanofiber diameters were found to be 284 ± 48 nm for PCL and 330 ± 104 nm for PCL/collagen matrices. The porosities were calculated as 85% for PCL and 90% for PCL/collagen matrices. The covalent immobilization of EGF onto the nanofibrous matrices was verified by the increase of surface atomic nitrogen ratio from 1.0 to 2.4% for PCL and from 3.7 to 4.7% for PCL/collagen. Moreover, EGF immobilization efficiencies of PCL and PCL/collagen matrices were determined as 98.5 and 99.2%, respectively. Human dermal keratinocytes (HS2) were cultivated on both neat and EGF immobilized PCL and PCL/collagen matrices to investigate the effects of matrix chemical composition and presence of EGF on cell proliferation and differentiation. EGF immobilized PCL/collagen matrices exerted early cell spreading and rapid proliferation. Statistically high expression levels of loricrin in HS2 cells cultivated on EGF immobilized PCL/collagen matrices were (p < 0.001) regarding superior differentiation ability of these cells compared to HS2 cells cultured on neat PCL and PCL/collagen matrices. In conclusion, this novel EGF immobilized PCL/collagen nanofibrous matrix could potentially be considered as an alternative dermal substitutes and wound healing material for skin tissue engineering applications.     

Prediction of equibiaxial loading stress in collagen-based extracellular matrix using a three-dimensional unit cell model

Mechanical signals are important factors in determining cell fate. Therefore, insights as to how mechanical signals are transferred between the cell and its surrounding three-dimensional collagen fibril network will provide a basis for designing the optimum extracellular matrix (ECM) microenvironment for tissue regeneration. Previously we described a cellular solid model to predict fibril microstructure–mechanical relationships of reconstituted collagen matrices due to unidirectional loads (Acta Biomater 2010;6:1471–86). The model consisted of representative volume elements made up of an interconnected network of flexible struts. The present study extends this work by adapting the model to account for microstructural anisotropy of the collagen fibrils and a biaxial loading environment. The model was calibrated based on uniaxial tensile data and used to predict the equibiaxial tensile stress–stretch relationship. Modifications to the model significantly improved its predictive capacity for equibiaxial loading data. With a comparable fibril length (model 5.9–8 μm, measured 7.5 μm) and appropriate fibril anisotropy the anisotropic model provides a better representation of the collagen fibril microstructure. Such models are important tools for tissue engineering because they facilitate prediction of microstructure–mechanical relationships for collagen matrices over a wide range of microstructures and provide a framework for predicting cell–ECM interactions.     

Diffusivity of 125I-calmodulin through collagen membranes: effect of source concentration and membrane swelling ratio

Diffusivity of 125I-calmodulin (MW congruent to 17,000) through collagen membranes was studied as a model for the release of macromolecules from collagen matrices. The diffusion coefficient of calmodulin through collagen membranes was determined from time-lag experiments conducted in a dialysis cell at 24 degrees C. Based on time-lag experiments, the diffusion coefficient was observed to be a function of source concentration and membrane swelling ratio after denaturation. The dependence of the diffusion coefficient on source concentration was consistent with a model involving calmodulin immobilization by the collagen membrane. At high source concentrations the diffusion coefficient of calmodulin through collagen membranes was observed to vary from about 10(-8) for uncrosslinked membranes to 10(-9) cm2/s for highly crosslinked membranes. Based on theoretical calculations, the release rate from collagen matrices may be altered by a factor of three. It was concluded that the release rate of biologically active molecules from collagen matrices can be controlled by varying the extent of crosslinking and the macromolecular concentration. Further studies are necessary to characterize the release of other macromolecules from collagen matrices.     

Evaluation of Lateral Mechanical Tension in Thin-Film Tissue Constructs

Fibroblast-populated collagen matrices provide a simplified tissue model for wound healing and development processes. A technology (CELLDRUM Technology) evaluating lateral mechanical tension in fibroblast-populated collagen matrices (tissue constructs) with a thickness of 1 mm was introduced. Defined mechanical boundary conditions together with the known number and orientation of the cells revealed precise data on the average tension exerted by a single cell. Circular cell-populated collagen gels were manufactured inside the CELLDRUM on top of a flexible membrane. The collagen matrix was then excited by a sound pulse. The resulting resonance oscillation was monitored by a laser-based deflection sensor and frequency and damping were analyzed giving information on mechanical properties of the tissue construct. Several evaluation experiments were performed. Calf serum enhanced contractile forces of fibroblasts dose dependently. After the gels were treated with cytochalasin D for 24 h, the cell forces were reduced by 42% of control. The remaining tension was attributed to the extracellular matrix remodeling occurring during cell growth and to other cytoskeletal structures like microtubules and intermediate filaments. We also found that only after a few hours of culture fibroblast-seeded collagen gels began developing significant mechanical tension. A mechanical tension profile of proliferating fibroblasts in collagen gels over culture time was obtained.     

生肌玉红胶原海绵修复创面损伤

背景：生肌玉红胶原海绵能显著促进创面愈合。 目的：观察生肌玉红胶原海绵对兔皮肤创面愈合的影响。 方法：在新西兰白兔背部制造3处全层皮肤缺损创面,分别以生肌玉红胶原海绵、贝复剂(重组碱性成纤维细胞生长因子外用溶液)、生理盐水修复。观察各组创面愈合时间、创面愈合率,检测创面修复组织内成纤维细胞数、血红素氧化酶1、转化生长因子β1 mRNA与蛋白及增殖细胞核抗原蛋白表达。 结果与结论：与贝复剂、生理盐水比较,生肌玉红胶原海绵可显著促进成纤维细胞增殖(P < 0.05),增加创面血红素氧化酶1、转化生子因子β1及增殖细胞核抗原的表达(P < 0.05),提高创面愈合率(P < 0.05),缩短创面愈合时间(P < 0.05)。证实生肌玉红胶原海绵能够促进创面修复,其作用机制可能是通过提高创面血红素氧化酶1、转化生长因子β1表达促进细胞增殖,增加成纤维细胞等创面修复细胞。     

Loading of collagen-heparan sulfate matrices with bFGF promotes angiogenesis and tissue generation in rats

The loading of biocompatible matrices with growth factors offers the opportunity to induce specific cell behavior. The attachment of heparan sulfate (HS) to these matrices may promote the binding, modulation, and sustained release of signaling molecules. In this study, basic fibroblast growth factor (bFGF) was bound to crosslinked collagenous matrices with and without covalently attached HS. The tissue response to these matrices was evaluated after subcutaneous implantation in rats. Attachment of HS to collagen matrices increased the bFGF binding capacity threefold and resulted in a more gradual and sustained release of the growth factor in vitro. bFGF primarily was located at the matrix margins. In vivo, the presence of HS without bFGF resulted in a transient vascularization, predominantly at the matrix periphery. Angiogenesis was further enhanced by combining HS with bFGF. In contrast to collagen-HS and collagen/bFGF matrices, collagen-HS/bFGF matrices remained highly vascularized throughout the matrix during the 10-week implantation period. In addition, these latter matrices revealed an intense and prolonged tissue response and considerably promoted the generation of new tissue. Foreign body reactions were only observed sporadically at this time interval. It is concluded that bFGF loading of collagen-HS matrices has additional value for those tissue-engineering applications that require enhanced angiogenesis and generation of new tissue.