神经生长因子和碱性成纤维细胞生长因子联用治疗坐骨神经损伤实验研究

INTRODUCTIONNowdays,manynervenutrientfactorswerefoundtohaverepaireffectonnerveinjury犤1.However,manyexperimentshaveconcen-tratedontheeffectofsinglefactor.Ourresearchwerefocusedoncombinationeffectofnervegrowthfactor(NGF)andbasicfibrob-lastgrowthfactor(bFGF)onsciaticnerveinjuryandprovidecluestoclinicaltreatment.MATERIALSANDMETHODSMaterialsExperimentanimalsandgroupdivision96femaleWistarrats,weighting220-240gwererandomlydividedintonormalsalinegroup,NGFgroup,bFGFgroupandNGF+bFGF…     

A polylactic acid non‐woven nerve conduit for facial nerve regeneration in rats

This study developed a biodegradable nerve conduit with PLA non‐woven fabric and evaluated its nerve regeneration‐promoting effect. The buccal branch of the facial nerve of 8 week‐old Lewis rats was exposed, and a 7 mm nerve defect was created. A nerve conduit made of either PLA non‐woven fabric (mean fibre diameter 460 nm), or silicone tube filled with type I collagen gel, or an autologous nerve, was implanted into the nerve defect, and their nerve regenerative abilities were evaluated 13 weeks after the surgery. The number of myelinated neural fibres in the middle portion of the regenerated nerve was the highest for PLA tubes (mean ± SD, 5051 ± 2335), followed by autologous nerves (4233 ± 590) and silicone tubes (1604 ± 148). Axon diameter was significantly greater in the PLA tube group (5.17 ± 1.69 µm) than in the silicone tube group (4.25 ± 1.60 µm) and no significant difference was found between the PLA tube and autograft (5.53 ± 1.93 µm) groups. Myelin thickness was greatest for the autograft group (0.65 ± 0.24 µm), followed by the PLA tube (0.54 ± 0.18 µm) and silicone tube (0.38 ± 0.12 µm) groups, showing significant differences among the three groups. The PLA non‐woven fabric tube, composed of randomly‐connected PLA fibres, is porous and has a number of advantages, such as sufficient strength to maintain luminal structure. The tube has demonstrated a comparable ability to induce peripheral nerve regeneration following autologous nerve transplantation. Copyright © 2012 John Wiley & Sons, Ltd.     

碱性成纤维细胞生长因子对大鼠神经损伤后肌肉的影响

目的研究碱性成纤维细胞生长因子(bFGF)对大鼠坐骨神经钳夹损伤后小腿三头肌的保护作用。方法42只大鼠随机等分成6组,钳夹对照:4周组(C4),8周组(C8),12周组(C12);bFGF用药:4周组(F4),8周组(F8),12周组(F12)。手术暴露坐骨神经,外科止血钳钳夹坐骨神经。实验组夹伤后即刻于损伤处神经干内分别注射bFGF,对照组注射等量生理盐水,术后在术侧腓肠肌注射药物,1次/d,直到实验结束。分别存活4,8,12周时,进行足印分析及坐骨神经功能指数(sciaticnervefunctionindex,SFI)测定实验;随后麻醉动物,20g/L多聚甲醛和12.5g/L戊二醛,经心灌注固定,切取小腿三头肌,称重,后取其中段,石蜡包埋、切片,光镜下测量小腿三头肌的横截面直径。结果大鼠坐骨神经钳夹损伤后各组之间小腿三头肌质量比结果不同,C4组0.708±0.015,F4组0.763±0.035,t=1.6,P<0.01;C8组0.903±0.032,F8组0.963±0.013,t=5.0,P<0.01;C12组0.920±0.073,F12组0.980±0.014,t=16.7,P<0.01。肌纤维直径不同,正常侧(15.2±0.6)μm,C4组(10.8±0.9)μm,F4组(12.2±0.7)μm,t=6.7,P<0.01,C8组(11.1±0.1)μm,F8组(13.5±0.9)μm,t=10.2,P<0.01,C12组(13.1±0.8)μm,F12组(14.2±1.0)μm,t=4.8,P<0.01,组间差异具有显著性意义。结论大鼠坐骨神经钳夹损伤后,bFGF能     

外源性碱性成纤维细胞生长因子对肠缺血再灌注大鼠肝脏内源性碱性成纤维细胞生长因子及其受体表达的影响

目的：通过观察外源性碱性成纤维细胞生长因子（ｂＦＧＦ）对缺血 再灌注大鼠肝脏内源性ｂＦＧＦ及碱性成纤维细胞生长因子受体（ＦＧＦＲ１）表达水平的影响,探讨ｂＦＧＦ调控内脏损伤修复的分子机制。方法：采用大鼠肠系膜上动脉夹闭模型,将动物随机分为假手术组、缺血即刻组、外源性ｂＦＧＦ治疗组及未治疗的再灌注６、２４ 和４８小时组。ｂＦＧＦ和ＦＧＦＲ１ 的表达水平采用免疫组织化学ＳＰ方法测定。结果：缺血 再灌注损伤后内源性ｂＦＧＦ和ＦＧＦＲ１ 表达水平均明显提高,分别在再灌注６小时和２４ 小时达峰值,４８小时后下降。应用外源性ｂＦＧＦ治疗后,在组织学损伤得到明显改善的同时,ｂＦＧＦ表达水平也较非治疗组明显提高,而ＦＧＦＲ１ 的表达水平无变化。结论：缺血 再灌注损伤诱导了内源性ｂＦＧＦ和ＦＧＦＲ１ 的表达,而外源性ｂＦＧＦ可能通过上调内源性ｂＦＧＦ的表达或其自身与ＦＧＦＲ１ 结合,调控肝损伤后的组织修复。     

碱性成纤维细胞生长因子对海马伞切断大鼠海马神经的影响

目的了解碱性成纤维细胞生长因子(bFGF)对海马伞切断造成的阿尔茨海默病(AD)模型大鼠海马齿状回神经发生的影响,探讨bFGF治疗AD的前景。方法36只SD大鼠随机分成正常对照组(n=12)、AD对照组(n=12)和AD处理组(n=12)。AD处理组及AD对照组大鼠左侧海马伞切断制造AD模型;正常对照组注射生理盐水。AD处理组造模后每天侧脑室注射bFGF共7d;AD对照组及正常对照组同时间注射生理盐水。BrdU标记增殖细胞。TUNEL方法标记DNA片段,原位检测凋亡细胞。计数海马齿状回BrdU阳性细胞与凋亡细胞数。结果AD处理组大鼠与AD对照组大鼠相比,海马齿状回BrdU阳性细胞增加犤两组在颗粒细胞层阳性细胞分别为(163±37),(53±5)个/切片平面;海马门(28.5±5.5),(12.3±2.8)个/切片平面;分子层(10.7±2.2),(6.0±1.4)个/切片平面犦,差异有非常显著性意义(F=103.4,83.4,33.4,P<0.01),而凋亡细胞差异无显著性意义(P>0.05)。AD对照组大鼠与正常对照组大鼠相比,海马齿状回BrdU阳性细胞数及凋亡细胞差异均无显著性意义(P>0.05)。结论bFGF可刺激AD模型大鼠海马神经发生。     

The efficacy of a novel collagen–gelatin scaffold with basic fibroblast growth factor for the treatment of vocal fold scar

Vocal fold scar remains a therapeutic challenge. Basic fibroblast growth factor (bFGF) was reported to have regenerative effects for vocal fold scar, although it has the disadvantage of rapid absorption in vivo. A collagen–gelatin sponge (CGS) can compensate for the disadvantage by providing a sustained release system. The current study evaluated the efficacy of CGS combined with bFGF on vocal fold scar, using rat fibroblasts for an in vitro model and a canine in vivo model. We prepared fibroblasts from scarred vocal folds (sVFs) in rats and showed that bFGF accelerated cell proliferation and suppressed expression levels of cleaved caspase 3 and α‐smooth muscle actin. Has 1, Has 3, Fgf2, Hgf and Vegfa mRNA levels were significantly upregulated, while Col1a1 and Col3a1 were dose‐dependently downregulated, with a maximum effect at 100 ng/ml bFGF. In an in vivo assay, 6 weeks after lamina propria stripping, beagles were divided into three groups: CGS alone (CGS group); CGS with bFGF (7 µg/cm²; CGS + bFGF group); or a sham‐treated group. Vibratory examination revealed that the glottal gap was significantly reduced in the bFGF group and the two implanted groups, whereas the CGS + bFGF group showed higher mucosal wave amplitude. Histological examination revealed significantly restored hyaluronic acid and elastin redistribution in the CGS + bFGF group and reductions in dense collagen deposition. These results provide evidence that CGS and bFGF combination therapy may have therapeutic potential and could be a promising tool for treating vocal fold scar. Copyright © 2015 John Wiley & Sons, Ltd.     

Human corneal fibroblast migration and extracellular matrix synthesis during stromal repair: Role played by platelet‐derived growth factor‐BB,basic fibroblast growth factor,and transforming growth factor‐β1

The development of treatments that modulate corneal wound healing to avoid fibrosis during tissue repair is important for the restoration of corneal transparency after an injury. To date, few studies have studied the influence of growth factors (GFs) on human corneal fibroblast (HCF) expression of extracellular matrix (ECM) proteins such as collagen types I and III, proteoglycans such as perlecan, or proteins implicated in cellular migration such as α5β1‐integrin and syndecan‐4. Using in vitro HCFs, a mechanical wound model was developed to study the influence of the GFs basic fibroblast GF (bFGF), platelet‐derived GF (PDGF‐BB) and transforming GF‐β1 (TGFβ1) on ECM protein production and cellular migration. Our results show that mechanical wounding provokes the autocrine release of bFGF and TGFβ1 at different time points during the wound closure. The HCF response to PDGF‐BB was a rapid closure due to fast cellular migration associated with a high focal adhesion replacement and a high expression of collagen and proteoglycans, producing nonfibrotic healing. bFGF stimulated nonfibrotic ECM production and limited the migration process. Finally, TGFβ1 induced expression of the fibrotic markers collagen type III and α5β1 integrin, and it inhibited cellular migration due to the formation of focal adhesions with a low turnover rate. The novel in vitro HCF mechanical wound model can be used to understand the role played by GFs in human corneal repair. The model can also be used to test the effects of different treatments aimed at improving the healing process. Copyright © 2016 John Wiley & Sons, Ltd.     

Repairing peripheral nerve defects with revascularized tissue‐engineered nerve based on a vascular endothelial growth factor‐heparin sustained release system

To enhance the angiogenic capacity of tissue‐engineered peripheral nerves, we have constructed revascularized tissue‐engineered nerves based on a vascular endothelial growth factor (VEGF)‐heparin sustained release system. However, the effects of the repair of large peripheral nerve defects are not known. In this study, we used the above revascularized tissue‐engineered nerve to repair large nerve defects in rats. The repair effects were observed through general observation, functional evaluation of nerve regeneration, ultrasound examination, neural electrophysiology, wet weight ratio of bilateral gastrocnemius muscle, histological evaluation, and quantitative real‐time polymerase chain reaction (PCR) analysis. The results showed that the tissue‐engineered peripheral nerve based on a VEGF‐heparin sustained release system can achieve early vascularization and restore blood supply in the nerve graft area. The realization of early vascularization in the area of the nerve defect greatly promotes the speed of nerve regeneration and reconstruction in the area of the nerve defect, which greatly advances the process of nerve repair and reconstruction and accelerates the restoration of the normal morphological structure and function of peripheral nerves.     

bFGF和NGF基因在大鼠脑震荡脑损伤中的表达研究

目的：探讨碱性成纤维细胞生长因子（bFGF）和神经生长因子（NGF）基因在大鼠实验性脑震荡脑损伤中的表达及意义。方法：采用Wistar雄性二级大鼠复制脑震荡动物模型，于伤后1d、3d、7d、14d及30d活杀取脑组织，经免疫组织化学和原位杂交等技术研究bFGF和NGFmRNA和蛋白在脑震荡中的变化规律。结果：100g组见典型脑震荡的临床表现。bFGF蛋白和mRNA于伤后1d表达增强，3-7d达高峰，14d后开始减少，30d仍高于正常水平。阳性部位见于大脑皮质、海马、丘脑和小脑神经元胞浆内。NGF蛋白和mRNA于伤后1d，损伤区大脑皮质、海马、丘脑和小脑神经元胞浆内呈强阳性反应，表达明显增多，3-30d持续呈强阳性至阳性，但随时间的推移，呈减少趋势。结论：bFGF基因表达参与脑震荡发生时脑组织损伤的病理过程，可能对神经细胞变性、坏死起重要调节作用；NGF基因表达参与脑震荡脑损伤和恢复的全过程，尤其在早期急性期起重要调节作用。     

Enhanced intestinal anastomotic healing with gelatin hydrogel incorporating basic fibroblast growth factor

Anastomotic leakage is a common complication of intestinal surgery. In an attempt to resolve this issue, a promising approach is enhancement of anastomotic wound healing. A method for controlled release of basic fibroblast growth factor (bFGF) using a gelatin hydrogel was developed with the objective of investigating the effects of this technology on intestinal anastomotic healing. The small intestine of Wistar rats was cut, end‐to‐end anastomosis was performed and rats were divided into three groups: bFGF group (anastomosis wrapped with a hydrogel sheet incorporating bFGF), PBS group (wrapped with a sheet incorporating phosphate‐buffered saline solution) and NT group (no additional treatment). Degradation profiles of gelatin hydrogels in vivo and histological examinations were performed using gelatin hydrogels with various water contents and bFGF concentrations to define the optimal bFGF dose and hydrogel biodegradability. The anastomotic wound healing process was evaluated by histological examinations, adhesion‐related score and bursting pressure. The optimal water content of the hydrogel and bFGF dose was determined as 96% and 30 µg per sheet, respectively. Application of bFGF significantly enhanced neovascularization, fibroblast infiltration and collagen production around the anastomotic site when compared with the other groups. Bursting pressure was significantly increased in the bFGF group. No significant difference was observed in the adhesion‐related score among the groups and no anastomotic obstruction and leakage were observed. Therefore controlled release of bFGF enhanced healing of an intestinal anastomosis during the early postoperative period and is a promising method to suppress anastomotic leakage. Copyright © 2013 John Wiley & Sons, Ltd.     

Acceleration of skin regeneration in full‐thickness burns by incorporation of bFGF‐loaded alginate microspheres into a CMCS–PVA hydrogel

Two important issues in skin tissue engineering are the vascularization and regeneration of the dermis. Basic fibroblast growth factor (bFGF) is known to promote angiogenesis and accelerate wound healing. Direct delivery of bFGF to the wound area, however, would lead to a loss of bioactivity. To this end, bFGF‐loaded alginate microspheres (Ms) were fabricated and incorporated into carboxymethyl chitosan (CMCS)–poly(vinyl alcohol) (PVA) to form a composite hydrogel. Scanning electron microscopy (SEM) results indicated that the incorporation of Ms does not significantly affect the inner structure of CMCS–PVA. In an in vitro study, the release of bFGF from Ms–CMCS–PVA in a sustained manner retained higher bioactivity over a 2‐week period. Full‐thickness burn wounds were created in the dorsal area of rats for in vivo evaluation of skin regeneration treated with CMCS–PVA hydrogel, with and without bFGF. Compared with the control, CMCS–PVA and bFGF–CMCS–PVA groups, the bFGF/Ms–CMCS–PVA group revealed significantly faster wound recovery rates, with re‐epithelialization and regeneration of the dermis. Moreover, the bFGF/Ms–CMCS–PVA group had the highest density of newly formed and mature blood vessels during the 2 mweek treatment period. The ability of the bFGF/Ms–CMCS–PVA hydrogel to accelerate wound healing in a full‐thickness burn model suggests its potential for use in dermal tissue regeneration. Copyright © 2015 John Wiley & Sons, Ltd.     

碱性成纤维细胞生长因子及血小板源性生长因子在人股骨颈骨折中的表达及相互关系

目的 研究股骨颈骨折后不同时期碱性成纤维细胞生长因子(bFGF)及血小板源性生长因子(PDGF)的表达及分布特点.方法 应用免疫组化PV超敏法对36例人股骨颈骨折标本中bFGF、PDGF蛋白进行检测,应用CMIAS真彩色医学图像分析系统对各组免疫组化结果进行吸光度(A)检测及分析,同时对bFGF、PDGF表达进行相关性分析.结果 ①伤后1周组9例,bFGF蛋白在骨折处间充质细胞、单核细胞、血管内皮细胞表达最为显著,A为(0.4076 ±0.0902);PDGF蛋白在间充质细胞内呈弱阳性表达,而在血管内皮细胞内呈强阳性表达,A为(0.2261 ±0.0636).伤后2周组9例,bFGF、PDGF表达于成纤维细胞、血管内皮细胞、新生的软骨细胞及基质、成骨细胞中,A分别为(0.6404±0.0920)和(0.7457±0.0756),与伤后1周比较,差异有统计学意义(P＜0.05,P＜0.01).伤后3周组9例,bFGF及PDGF蛋白表达的OD分别为(0.7168 ±0.1346)和(0.8033.±0.0491),与伤后2周相比差异无统计学意义(P均＞0.05).伤后4周组9例,成熟的骨组织、软骨组织中bFGF、PDGF蛋白均呈弱阳性或阴性反应,但幼稚骨组织、软骨组织中则呈阳性表达,OD分别为(0.5374 ±0.1210)和(0.7068±0.1255),但表达程度低于伤后3周(P均＜0.05).②股骨颈骨折后1、2、3、4周bFGF与PDGF蛋白表达均成正相关(r分别为0.792、0.834、0.880、0.766,P均＜0.05).结论 ①bFGF在骨折愈合早期能诱导间充质细胞、成骨细胞、软骨细胞及血管内皮等细胞的分裂、增殖,促进新生血管及新骨的生成.②PDGF是骨细胞调节剂,可刺激软骨细胞和成骨细胞的增殖、分化并可间接地诱导血管内皮细胞增殖与新生血管生成.③bFGF及PDGF均为骨性生长因子,二者互相促进,共同调节成骨细胞及血管增殖和分化,最终完成骨折修复过程.     

Nanofibrous gelatine scaffolds integrated with nerve growth factor‐loaded alginate microspheres for brain tissue engineering

Neural regeneration research is designed in part to develop strategies for therapy after nerve damage due to injury or disease. In this study, a new gelatine‐based biomimetic scaffold was fabricated for brain tissue engineering applications. A technique combining thermally induced phase separation and porogen leaching was used to create interconnected macropores and nanofibrous structure. To promote tissue regeneration processes, the scaffolds were integrated with nerve growth factor (NGF)‐loaded alginate microspheres. The results showed that nanofibrous matrix could only be obtained when gelatine concentration was at least 7.5% (w/v). The scaffold with a modulus value (1.2 kPa) similar to that of brain tissue (0.5–1 kPa) was obtained by optimizing the heat treatment time, macropore size and gelatine concentration. The encapsulation efficiencies of NGF into 0.1% and 1% alginate microspheres were 85% and 100%, respectively. The release rate of NGF from the microspheres was controlled by the alginate concentration and the poly(L‐lysine) coating. The immobilization of the microspheres in the scaffold reduced burst release and significantly extended the release period. The nanofibrous architecture and controlled release of NGF from the microspheres induced neurite extension of PC12 cells, demonstrating that the released NGF was in an active form. The results suggest that the scaffolds prepared in this study may have potential applications in brain tissue engineering due to topologic and mechanical properties similar to brain tissue and pore structure suitable for cell growth and differentiation. Copyright © 2016 John Wiley & Sons, Ltd.     

膜联蛋白-1及碱性成纤维细胞生长因子在前列腺癌中的表达

目的探讨膜联蛋白-1及碱性成纤维细胞生长因子在前列腺癌组织的表达及意义。方法 61例前列腺癌组织、40例癌旁组织、40例正常前列腺组织,应用免疫组织化学法检测膜联蛋白-1及碱性成纤维细胞生长因子在3种组织中的表达。结果正常前列腺癌组织、癌旁组织及前列腺组织中膜联蛋白-1阳性表达率分别为19.67%,22.50%及72.50%,碱性成纤维细胞生长因子阳性表达率分别为70.49%,42.50%及25.00%,差异有统计学意义(P<0.01);碱性成纤维细胞生长因子阳性表达在年龄、肿瘤大小、组织分化程度、肿瘤浸润深度、淋巴结转移、TNM分期及远期转移上差异有统计学意义(P<0.05)。结论联合检测膜联蛋白-1及碱性成纤维细胞生长因子有助于前列腺癌的早期诊断与治疗。     

表皮生长因子和碱性成纤维细胞生长因子联合应用于深度褥疮的护理研究

[目的]探讨表皮生长因子和碱性成纤维细胞生长因子联合应用于深度褥疮的护理效果。[方法]选择褥疮45例处,其中Ⅱ期褥疮19例处、Ⅲ期21例处、Ⅳ期5例处,随机分为实验组和对照组,实验组将表皮生长因子和碱性成纤维细胞生长因子联合喷洒于褥疮创面,结合微波治疗;对照组用抗生素药液湿敷,予红外线局部照射,观察创面修复情况及愈合速度。[结果]实验组创面愈合速度为0.1mm/d～0.3mm/d,对照组为0.07mm/d～0.15mm/d,差异有统计学意义(P<0.05);实验组有效率高于对照组。[结论]表皮生长因子和碱性成纤维细胞生长因子联合应用于深度褥疮的治疗,疮面愈合效果好于传统的抗生素湿敷及红外线照射法。     

EGF和bFGF在大鼠不同发育阶段肠道定位和表达特征的比较研究

目的：研究表皮细胞生长因子（EGF）和碱性成纤维细胞生长因子（bFGF）在胚胎、新生以及成年3个不同发育阶段,大鼠肠道的表达特征及其可能的生物学意义。方法：取胚胎、新生和成年大鼠小肠,经4％多聚甲醛固定、包埋与切片后,用链酶卵白素免疫组织化学研究EGF和bFGF两种生长因子的定位与表达特征。结果：EGF的阳性表达可见于胚胎、新生以及成年3个不同发育阶段大鼠小肠,主要位于小肠黏膜上皮细胞、固有层细胞和膜肌层细胞胞浆,其表达强度为阳性。bFGF在胚胎、新生与成年大鼠小肠表达的定位与EGF类似,但在整个发育过程中表达为弱阳性或阳性。结论：EGF在不同发育阶段大鼠小肠呈强阳性表达,表明了它对肠道的发生、表型维持以及损伤后的修复十分重要。与EGF相比,大鼠胚胎期、新生以及成年期bFGF低表达特征,表明bFGF参与了动物不同发育阶段肠道的发育过程,但其作用可能较EGF为弱。     

垂体肿瘤转化基因及碱性成纤维细胞生长因子在乳腺癌组织中的表达及意义

目的研究垂体肿瘤转化基因（PTTG）及碱性成纤维细胞生长因子（bFGF）在乳腺癌中的表达及意义。方法收集乳腺癌患者手术标本72例,癌旁正常乳腺组织20例。通过免疫组化方法检测PTTG和bFGF的表达,随访观察发生转移情况及5年生存率。结果 PTTG及bFGF在正常乳腺组织中呈阴性表达,在乳腺癌组织中呈阳性表达,高表达者其发生远处转移的几率及死亡率均明显高于低表达者,且PTTG及bFGF间存在相关关系。结论 PTTG及bFGF参与乳腺癌的形成及发展,其表达高低与乳腺癌的恶性程度及预后相关。在标本中对其行半定量分析可对乳腺癌患者的治疗及预后提供重要的参考。     

Effect of basic fibroblast growth factor released from chitosan–fucoidan nanoparticles on neurite extension

Exogenous growth factors are an integral part of an effective nerve tissue‐engineering strategy. Basic fibroblast growth factor (bFGF) has a marked positive effect on angiogenesis and neuronal cell survival. However, bFGF is limited by its short half‐life and easy degradation by enzymes. Therefore, in this study novel biodegradable chitosan–fucoidan nanoparticles (CS–F NPs) were designed to carry bFGFs and maintain their activities. The experimental results indicated that chitosan and fucoidan form stable nanoparticles approximately 200 nm in size via electrostatic interactions. Additionally, the effectiveness of nanoparticles is related to their chitosan:fucoidan weight ratio. The CS–F NPs control the release of bFGFs and protect bFGF from deactivation by heat and enzymes. In vitro cell studies demonstrate that CS–F NPs have no cytotoxicity to PC12 cells, as the concentration of NPs is 125 ng/ml. Moreover, the CS–F NPs significantly decrease the amount of bFGF needed for neurite extension. The cumulative release of bFGF from CS–F NPs at 24 h is 0.168 ng/ml, markedly lower than that in solution (4.2 ng/ml). Importantly, CS–F NPs are potential carriers for delivering bFGFs for nerve tissue engineering. Copyright © 2013 John Wiley & Sons, Ltd.     

Gelatin‐based hydrogel for vascular endothelial growth factor release in peripheral nerve tissue engineering

Hydrogels are promising materials in regenerative medicine applications, due to their hydrophilicity, biocompatibility and capacity to release drugs and growth factors in a controlled manner. In this study, biocompatible and biodegradable hydrogels based on blends of natural polymers were used in in vitro and ex vivo experiments as a tool for VEGF‐controlled release to accelerate the nerve regeneration process. Among different candidates, the angiogenic factor VEGF was selected, since angiogenesis has been long recognized as an important and necessary step during tissue repair. Recent studies have pointed out that VEGF has a beneficial effect on motor neuron survival and Schwann cell vitality and proliferation. Moreover, VEGF administration can sustain and enhance the growth of regenerating peripheral nerve fibres. The hydrogel preparation process was optimized to allow functional incorporation of VEGF, while preventing its degradation and denaturation. VEGF release was quantified through ELISA assay, whereas released VEGF bioactivity was validated in human umbilical vein endothelial cells (HUVECs) and in a Schwann cell line (RT4‐D6P2T) by assessing VEGFR‐2 and downstream effectors Akt and Erk1/2 phosphorylation. Moreover, dorsal root ganglia explants cultured on VEGF‐releasing hydrogels displayed increased neurite outgrowth, providing confirmation that released VEGF maintained its effect, as also confirmed in a tubulogenesis assay. In conclusion, a gelatin‐based hydrogel system for bioactive VEGF delivery was developed and characterized for its applicability in neural tissue engineering. Copyright © 2014 John Wiley & Sons, Ltd.     

重组人碱性成纤维细胞生长因子对缺血心肌的保护作用

目的：探讨重组人碱性成纤维细胞生长因子（rhbFGF）在急性心肌缺血中对缺血心肌细胞的保护作用。方法：无菌条件下开胸结扎兔冠状动脉左前降支（LAD），建立急性心肌梗死动物模型；制备rhbFGF蛋白，将其直接四点注入兔缺血心肌内，通过心肌酶学及电镜病理观察rhbFGF对缺血心肌的保护作用。结果：①血清心肌酶学观察：结扎LAD后24h及48h心肌酶AST、LDH、LDH-1、CK、CK-MB、HBDH与术前比较显著升高，术后48h rhbFGF组心肌酶CK-MB较生理盐水对照组明显降低；术后48h与24h相比较，LDH-1在生理盐水对照组升高而在rhbFGF组降低；②电镜观察：与生理盐水对照组相比rhbFGF组心肌细胞间可见大量毛细血管生长，新生血管周围可见趋于正常的心肌细胞。结论：rhbFGF可缩小心肌梗死面积，对缺血心肌细胞可能有直接的保护作用。