血管内皮生长因子转染内皮祖细胞治疗大鼠缺血后肢的研究

目的 使用血管内皮生长因子(VEGF)转染内皮祖细胞(EPC)治疗大鼠缺血后肢,观察EPC、VEGF转染EPC对大鼠缺血后肢的新生血管和肢体成活的影响.方法 制作SD大鼠后肢缺血模型,将动物随机分为3组,每组6只.将构建的VEGF基因真核表达载体转染入骨髓来源的EPCs后通过尾静脉注射人大鼠体内,并与使用磷酸盐缓冲液(PBS)或EPC的动物进行比较,观察转染VEGF的EPCs在缺血部位的聚集和形成新生血管的情况.结果 (1)动物总残肢率比较,CELL组、VEGF组较PBS组明显增加的肢体恢复率(P<0.05),CELL组肢体恢复率较VEGF组差(P<0.05).(2)毛细血管密度与PBS组比较,各时间点中CELL、VEGF组MVD均明显增多(P<0.05).(3)缺血肢体VEGFa的表达:VEGF组的VEGF蛋白表达较PBS组、CELL组、明显增多(P<0.05);(4)手术后7、14、28 d,与PBS对照组比较,CELL、VEGF组细胞的血流灌注有较大程度的恢复(P<0.01).结论 VEGFa基因转染EPCs对缺血部位的血管新生有重要影响,联合应用VEGFa基因和EPCs治疗缺血后肢有较好的协同作用.     

血管内皮生长因子-碱性成纤维细胞生长因子基因治疗家兔肢体缺血的研究

目的　了解血管内皮生长因子 (VEGF)和碱性成纤维细胞生长因子 (bFGF)联合克隆基因 (VEGF bFGF)治疗兔下肢动脉缺血模型后新生血管和侧支形成状况。方法　应用 40只家兔制成下肢缺血模型 ,其中VEGF bFGF组 10只 ,VEGF组 12只 ,空载体组 8只 ,生理盐水 (NS)组 10只。构建pcDNA3 /VEGF和pcDNA3 /VEGF bFGF真核表达载体。转染缺血部位肌组织 ,行下肢血管造影。结果　血管造影计数显示 ,VEGF bFGF组在转染后 14d(1.98± 0 .2 2 ) ,2 8d (1.81± 0 .5 2 ) ,5 6d(2 .2 1± 0 .44 )和 3个月 (2 .10± 0 .2 2 ) ;VEGF组在 2 8d(1.3 8± 0 .2 9) ,5 6d(1.94± 0 .2 5 )和 3个月 (2 .2 4± 0 .3 1) ,新生血管形成较对照组显著增加 (P <0 .0 5 )。结论　VEGF bFGF真核表达载体可以获得局部高效表达 ,刺激新生血管生成 ,建立侧枝循环 ,改善肢体缺血。     

大鼠缺血后肢骨骼肌血管内皮生长因子及其受体的表达

目的 研究大鼠缺血后肢侧枝代偿和血管内皮生长因子（VEGF）及其受体表达的动态变化。为外源性VEGF治疗下肢缺血性疾病提供理论依据。方法 切除SD大白鼠右后肢全长股动脉，随机分为9个时间组：造模后1、3d、1、2、3、4、6、8及12周，各组5只动物。分别于造模前后和观察期末检测双后肢大、小腿肌肉Fit-1、Flk-1蛋白及mRNA表达，各组观察期末实验动物后肢动脉DSA检查。结果 （1）缺血后3d，5只大鼠右后肢出现溃疡（11．11％）；2周后，4只大鼠后肢溃疡愈合，而1只趾端坏疽（2．22％）。（2）缺血后2周，患肢侧枝形成达到高峰，12周时仍可见侧支血管显影。（3）缺血早期（3周内），VEGF及其受体的表达均较健侧显著增强（P〈0．05）；缺血中期（3～8周）。VEGF和Flt-1表达迅速下降，Flk-1仍表达；缺血后期（8周后），VEGF及其受体的表达均低至极低水平，与对侧差异无统计学意义（P〉0．05）。结论（1）肢体缺血后自身的血管新生不能完全满足缺血组织的需要。（2）缺血早期外源性的VEGF补充是不必要的；缺血中期补充VEGF是适宜的；缺血后期在应用VEGF治疗的同时，也需要干预受体的表达。     

碱性成纤维细胞生长因子促进兔缺血后肢血管新生的实验研究

目的:了解局部应用碱性成纤维细胞生长因子(bFGF)对促进兔缺血后肢血管新生的作用。方法:25只日本大耳白兔随机分2组,外科结扎切断各兔股动脉及其分支,制作兔后肢缺血模型。试验组各兔在缺血后肢肌肉内多次注射重组人bFGF蛋白(n=15);对照组给予等剂量生理盐水(n=10)。术后4周,各兔行腹主动脉造影观察侧支血管形成情况,取内收肌和腓肠肌肌肉行病理切片HE染色应用图像分析系统统计血管密度,并用免疫组织化学方法检测内收肌和腓肠肌中VEGF阳性表达的血管数。结果:试验组兔侧支循环血管条数、血管密度及VEGF阳性表达的血管数均大于对照组(P<0.01),缺血状态得到改善。结论:在兔缺血后肢肌肉中注射bFGF蛋白可促进血管新生,增加兔缺血后肢血液灌注,改善肢体缺血状态。     

神经生长因子基因转染对缺血肢体血管生成和骨骼肌纤维重塑的影响

目的观察神经生长因子(NGF)对缺血肢体血管生成和骨骼肌纤维重塑的影响,探讨NGF与血管内皮生长因子(VEGF)在血管生成中的关系。方法 18只小鼠随机分为正常对照组、空白对照组和NGF治疗组,每组各6只。建立小鼠左后肢缺血模型,术后第7 d对NGF组进行基因转染。术后第21 d时对3组小鼠左后肢缺血进行评估,然后取腓肠肌组织进行HE染色、增殖细胞核抗原(PCNA)和CD34免疫组织化学染色,ELISA法检测腓肠肌组织中NGF、VEGF蛋白表达量,肌球蛋白ATP酶染色分析肌纤维类型。结果术后第21 d时,NGF组的左后肢肌肉萎缩程度弱于空白对照组,左后肢缺血评分明显低于空白对照组(P0.05),内皮细胞增殖指数、毛细血管密度、NGF和VEGF表达量均明显高于空白对照组(P0.05),Ⅰ型肌纤维比例也明显高于空白对照组(P0.05)。结论 NGF基因转染能够促进缺血肢体NGF、VEGF表达和血管生成,诱导肌纤维向Ⅰ型重塑,相关分子调控机制仍需进一步研究。     

血管内皮细胞生长因子基因转染血管内皮祖细胞移植提高移植脂肪存活率的实验研究

目的探讨血管内皮细胞生长因子165(VEGF165)基因转染血管内皮祖细胞(EPCs)移植促进游离移植的脂肪组织的血管新生,提高移植脂肪组织存活率。方法体外分离、培养人脐血中EPCs,利用脂质体介导VEGF165基因体外转染EPCs,然后与来自人体的脂肪组织混合移植于裸鼠背部,裸鼠随机分为3组:VEGF165基因转染组、EPCs组及M199培养基对照组。结果脐血中分离培养的EPCs表达CD34、血管内皮细胞生长因子受体及CD133;VEGF165基因转染EPCs体外及体内检测均有VEGF165蛋白的表达。VEGF165基因转染组、EPCs组中,EPCs整合到缺血部位新生血管中,与对照组的脂肪组织存活率分别为(96.2±8.6)%、(75.3±6.8)%和(40.2±2.5)%(P<0.05),VEGF165基因转染组与EPCs组脂肪组织周边区毛细血管密度有显著差异(P<0.05),均高于对照组(P<0.05)。术后3个月时3组脂肪组织周边区的EPCs密度分别为(196±16)个/mm2、(95±11)个/mm2、0个/mm2(P<0.05)。结论脐血中的EPCs体外培养后移植体内可促进游离移植的脂肪组织的血管新生,提高存活率,而转染VEGF165基因的EPCs具有更强的促血管新生的作用。     

血管内皮生长因子定向转染诱导缺血心肌血管生成的研究

目的观察血管内皮生长因子（VEGF）质粒直接心肌注射对兔急性心肌缺血后侧支循环形成的影响。方法建立兔左冠状动脉结扎的急性心肌缺血模型，取缺血边缘区以先期构建的真核表达质粒pcDNA3／VEGF165和真核载体pcDNA3的DNA分别多点心肌注射，给药后2、4周取材分别行逆转录-聚合酶链反应（RT-PCR）和蛋白浓度分析、苏木素-伊红（HE）染色、VEGF染色。结果治疗组VEGF165 mRNA含量较对照组明显增多；蛋白浓度分析转染后VEGF165显著增多，高峰出现于实验后2周；治疗组缺血心肌新生血管数目明显多于对照组。结论VEGF165外源性基因能在转染心肌细胞后成功表达，促进了缺血心肌血管新生和侧支循环形成。     

转染血管内皮生长因子基因的小鼠NIH3T3细胞移植促进皮瓣早期血运重建的研究

目的探讨转染血管内皮生长因子（VEGF）基因的小鼠NIH3T3细胞移植对缺血皮瓣的血管新生和皮瓣存活率的影响。方法体外PcDNA3．1（-）／VEGF165质粒转染小鼠NIH3T3细胞,免疫组化方法检测小鼠NIH3T3细胞体外表达VEGF的情况,CM-DiI标记小鼠NIH3T3细胞。将小鼠随机分为3组：A组[PcDNA3．1（-）／VEGF165质粒转染的NIH3T3细胞移植]、B组（单纯NIH3T3细胞移植）、C组（单纯DMEM培养基注射）。每只小鼠背侧皮下按组分别注射细胞悬液和培养基,注射后酶联免疫吸附（ELISA）法连续检测大鼠血浆VEGF浓度,注射后第4天掀起一个蒂在尾侧的4．0cm×1．5cm的随意皮瓣。术后第7天分别观察皮瓣的存活率、血流灌注、皮瓣毛细血管密度、NIH3T3细胞在皮瓣内的分布和存活情况。结果转染VEGF165基因的小鼠NIH3T3细胞体外和体内检测均高表达VEGF165蛋白。A组的皮瓣存活率、毛细血管密度、血流灌注比值均显著高于另外两组（P〈0．05）。结论转染VEGF基因的小鼠NIH3T3细胞皮下移植可促进缺血皮瓣的血管新生,提高存活率。     

血管内皮生长因子基因转染血管内皮祖细胞治疗肢体缺血的实验研究

目的利用血管内皮生长因子（vascular endothelial growth factor,VEGF-165）基因转染体外诱导的血管内皮祖细胞（endothelial progenitor cells,EPCs）,并移植到下肢缺血的新西兰兔体内,观测其促进血管新生,改善肢体缺血的效果。方法（1）梯度离心法分离兔骨髓单个核细胞,然后用含有VEGF、bFGF、IGF-1的M199培养液诱导培养EPCs。并以免疫荧光、透射电镜等方法进行鉴定。（2）用携带VEGF165基因的腺病毒质粒（Adv-GFP-VEGF165）转染所培养的细胞,ELISA法检测上清液中VEGF蛋白的表达。（3）制作兔下肢缺血模型,并将其随机分为A、B、C 3组,分别移植EPCs、VEGF165基因转染后的EPCs、M199培养基,多种方法检测移植效果及局部整合情况。结果（1）自兔骨髓诱导出梭形贴壁细胞,免疫荧光及电镜检测证实为EPCs。（2）Adv-GFP-VEGF165成功转染EPCs,ELISA法检测转染VEGF165后的EPCs其上清液中VEGF蛋白浓度明显升高。（3）Brdu示踪显示移植细胞整合到缺血局部,CTA及免疫组化检查显示VEGF-165基因转染后的EPCs移植后其改善肢体缺血效果优于其他两组。结论VEGF基因转染EPCs后能改进EPCs质量,移植后促血管新生能力增强,其效果优于未转染组。     

骨髓间充质干细胞联合血管内皮生长因子基因治疗肢体缺血的实验研究

目的 观察骨髓间充质干细胞(bone mesenchymal stem cell,BMSC)联合血管内皮生长因子(vascular endothelial growth factor,VEGF)基因治疗对家兔肢体缺血模型的疗效.方法 切除新西兰兔右后肢全长股浅动脉并结扎股深动脉以建立兔后肢缺血模型,随机分为空质粒对照组(EP组)、骨髓间充质干细胞组(BMSC组)、VEGF基因治疗组(VEGF组)及联合治疗组(BV组),每组各8只.分别于治疗后28 d及30 d进行动脉造影及VEGF免疫组化染色.结果 EP组、BMSC组及VEGF组的新生血管计数组间比较差异无统计学意义(P＞0.05).BV组的新生血管计数较其余3组明显增加,差异有统计学意义(F=35.47,P＜O.01).BMSC组及VEGF组的VEGF免疫组化染色呈阳性表达,与EP组比较差异有统计学意义(F=764.32,P＜0.01).BV组的VEGF免疫组化染色呈强阳性表达,与其余3组比较差异有统计学意义(F =764.32,P＜0.01).结论 BMSC联合VEGF基因治疗兔肢体缺血可使VEGF获得稳定而有效的表达,从而改善肢体缺血.     

应用转血管内皮生长因子基因治疗肢体缺血的研究

目的研究肌肉内转血管内皮生长因子(VEGF)基因治疗肢体缺血的可行性,比较各种治疗方法的疗效. 方法雄性新西兰大白兔50只,完全切除股动脉后随机分为3组.实验组为明胶海绵携载法转基因组(n=18)和肌肉内注射转基因组(n=18);只注射pcDNA3为对照组(n=14).通过直接注射法及明胶海绵携载法将构建的质粒pcDNA3-VEGF121基因转入缺血肌肉内,立即测定各组肢体髂内动脉血流量,在术后2天,1、2、3和4周应用逆转录-聚合酶链反应(RT-PCR)技术测定基因表达,术后30天通过测定缺血肢体髂内动脉血流量、动脉血管造影及组织学观察测定血管密度,评价侧支循环变化. 结果术后2天,转VEGF基因治疗的两实验组均测到基因表达,并均维持2周.术后立即测定的髂内动脉血流量各组间无明显差异.术后30天,缺血肢体髂内动脉血流量、肢体血管造影血管数目和肌肉组织血管密度转VEGF基因的两实验组均比对照组明显增高,差异有统计学意义(P<0.01),明胶海绵携载组较直接注射组亦有明显增高,差异有统计学意义(P＜0.05). 结论肌肉内转VEGF基因治疗可促进急性缺血肢体侧支循环、改善血供,明胶海绵携载法较直接注射法有更好的疗效.     

Induction of angiogenesis by cationic lipid-mediated VEGF165 gene transfer in the rabbit ischemic hindlimb model

PURPOSE: The purpose of this study was to test the efficacy of a new cationic lipid formulation coupled with the cDNA encoding for the 165-residue form of vascular endothelial growth factor (VEGF(165)) to induce neovascularization and enhance blood flow in the rabbit ischemic hindlimb model. METHODS: Two days after removal of their right femoral arteries, rabbits received intramuscular injections of different concentrations of VEGF(165) or saline solution in the ischemic thigh. Tissue perfusion and increased neovascularization of the ischemic limb were assessed weekly on the basis of the calf blood pressure ratio for the ischemic/nonischemic limbs, regional blood flow to the skeletal muscles as measured with radioactive microspheres, postmortem angiography, and histology. RESULTS: At weeks 1 and 2 after surgery, animals treated with 1000 microgram of VEGF(165) had a 1.5-fold increase and a 2.5-fold increase, respectively, in the regional blood flow to both the adductor and gastrocnemius muscles of the ischemic limb. The blood pressure ratio was also greater in the treated animals than in the controls at weeks 2 and 3 after surgery. Early neovascularization in the VEGF(165) group was further documented at week 1 after surgery by more angiographically recognizable collateral vessels (angioscores were 64.13 +/- 2.51 and 38.28 +/- 3.82 for VEGF(165) and saline solution, respectively; P <.001) and by a threefold increase in the number of capillaries (vascular density) relative to the controls (P <.005). CONCLUSIONS: Intramuscular administration of a single dose of plasmid-liposomes encoding for VEGF(165) accelerates angiogenesis and increases blood flow in the rabbit hindlimb ischemic model. Therefore, this nonviral vector could be recommended for further testing for use in therapeutic angiogenesis.     

Autologous skeletal myoblasts transduced with a new adenoviral bicistronic vector for treatment of hind limb ischemia

OBJECTIVE: We aimed to achieve angiogenic synergism between human vascular endothelial growth factor 165 (VEGF 165 ) and angiopoietin-1 (Ang-1) using a new adenoviral bicistronic vector concurrently with cell therapy to repair an ischemically damaged hind limb in a rabbit model. METHODS: Rabbit autologous primary skeletal myoblasts were isolated and labeled with retrovirally transduced LacZreporter gene, 4,6-diamidino-2-phenylindole (DAPI), and 5-bromo-2'-deoxyuridine (BrdU). Hind limb ischemia was created in 48 female New Zealand White rabbits by means of femoral artery ligation at 8 different places, and was assessed at angiography. Animals were randomized to receive intramuscular injection of either Dulbeco's Modified Eagle Medium (DMEM;group 1, n = 8), nontransduced myoblasts (group 2, n = 10), or myoblasts transduced with Ad-Null (group 3, n = 10), Ad-VEGF (group 4, n = 10), or Ad-Bicis (group 5, n = 8). Six weeks after treatment neovascularization in the limb was assessed at angiography. The animals were euthanized, and tissue was harvested for histologic study. RESULTS: Extensive transplanted myoblast survival was observed in all cell-transplanted groups, as visualized with DAPI, BrdU, and LacZ staining. Angiographic blood vessel count revealed enhanced neovascularization in group 5 (25.14 +/- 5.14) compared with group 4 (13.62 +/- 4.52), group 3 (6.09 +/- 0.09), group 2 (4.67 +/- 3.49), and group 1 (3.18 +/- 7.76). Immunostaining for von Willebrand factor confirmed significantly increased capillary density ( P < .01) at high-power microscopic field in group 5 (19.04 +/- 1.59) compared with group 4 (15.31 +/- 1.55), group 3 (6.53 +/- 0.97), group 2 (5.69 +/- 0.51), and group 1 (3.03 +/- 0.20). CONCLUSION: Simultaneous expression of VEGF and Ang-1 from bicistronic vector transduced skeletal myoblasts potently stimulated enhanced functional neovascularization in a rabbit model of limb ischemia.     

Gene transfer of naked VEGF plasmid induces the formation of microvessels but not mature collaterals in ischaemic limb muscles

Summary   Background: Several studies have demonstrated increased numbers of angiographically detectable collaterals after vascular endothelial growth factor (VEGF) gene transfer. However, VEGF appears to be insufficient for stimulating the growth of mature blood vessels. Therefore, we decided to reinvestigate in what way the VEGF gene transfer to rabbit ischaemic muscle can restore blood flow impaired by femoral artery excision. Methods: Naked DNA, either control plasmid (pSVβgal) or pSG5-VEGF₁₆₅ (harbouring human VEGF cDNA), was injected into adductor magnus muscle. Results: Human VEGF₁₆₅ mRNA was detected in the ischaemic muscle injected with pSG5-VEGF₁₆₅, and human VEGF protein was present in the blood plasma of the same animals but not in rabbits treated with control plasmid. However, rabbit VEGF synthesis was also enhanced in ischaemic legs of both β-gal and VEGF-treated animals. In spite of the augmented generation of endogenous VEGF, the local blood flow decreased to 75±13.9 % (of flow before excision) after 28 days in pSVβgal injected animals, whereas it was preserved (97.3±15 %) in pSG5-VEGF₁₆₅ treated rabbits (P<0.02). Muscles of rabbits treated with pSG5-VEGF₁₆₅ showed a significantly higher number of microvessels in comparison to ischaemic muscles treated with pSVβgal (230±66 vessels/mm² vs 134±48;P<0.01), but angiographic analysis did not demonstrate significant differences in the number of collaterals between animals. Conclusions: The restoration of blood flow is most probably due to increased local angiogenesis and not to the formation of stable collateral vessels.      

Enhanced angiogenesis and growth of collaterals by in vivo administration of recombinant basic fibroblast growth factor in a rabbit model of acute lower limb ischemia: dose-response effect of basic fibroblast growth factor.

The purpose of this study was to evaluate the effects of exogenous recombinant basic fibroblast growth factor (bFGF) on angiogenesis in severely ischemic tissue beds. We used a two-stage procedure to produce severe ischemia of the hindlimb of 34 New Zealand rabbits. The ischemic hindlimb received intramuscular injection of saline (group A), 1 microgram bFGF (group B), or 3 micrograms bFGF (group C), daily for 2 weeks. Tissue perfusion, skeletal muscle infarction, angiogenesis, and collateral growth were assessed by angiography, transcutaneous oximetry (TcPO2), quantitative spectrophotometric assay of triphenyltetrazolium chloride reduction in muscle, capillary density (capillaries per square millimeter), and capillary per muscle fiber ratio. There were no significant differences in baseline TcPO2 among the three groups for both thigh and calf measurements. Angiography revealed extensive perfusion of the left hindlimb in all the assessed bFGF treated animals. Both thigh and calf TcPO2 values showed a significant increase in all groups over the 14 days ischemia was induced (p less than 0.0001), but the two treatment groups exhibited a much more rapid rise in TcPO2 than the control group (p less than 0.0001). The capillaries per square millimeter and capillaries per muscle fiber ratios were significantly increased in all posttreatment measurements for all animals that received bFGF. The treatment groups with bFGF had a significant (p = 0.025) increase in thigh muscle viability compared with controls based on triphenyltetrazolium chloride reduction. Whereas there was evidence of muscle infarction in both the thighs of groups A and B, there was none in group C.(ABSTRACT TRUNCATED AT 250 WORDS)     

HIV-based vectors and angiogenesis following rabbit hindlimb ischemia

BACKGROUND: Numerous medical and surgical options exist for the treatment of vessel ischemia, which some patients fail or cannot tolerate. These investigations were designed to determine the effects of lentiviral-delivered vascular endothelial-derived growth factor (VEGF) and angiopoietin-2 (Ang-2) on collateralization in a rabbit model of hindlimb ischemia. MATERIALS AND METHODS: Self-inactivating human immunodeficiency virus (HIV)-based vectors were constructed encoding VEGF or Ang-2, co-transfected with vesicular stomatitis virus glycoprotein (VSV G) into 293T cells, and vector supernatants (1 x 10(8) IU/ml after concentration) were harvested. New Zealand white rabbits had ligation of either the right or left external iliac artery and excision of the ipsilateral femoral artery. Ten days later, empty, VEGF, or VEGF+Ang-2 vector supernatant was injected intramuscularly (IM) into the ipsilateral thigh. Ankle systolic blood pressure (SBP) ratios were recorded and venous blood samples collected on postoperative days (POD) 10, 25, and 40. On POD 40, run-off angiography was performed to measure vessel collateralization. Capillary density was determined by thin sectioning of muscle. RESULTS: A significant increase was noted in SBP in the VEGF-treated animals over time. Capillary density was not elevated despite significantly increased large vessel collateralization in rabbits receiving VEGF, which was counteracted by Ang-2. Antibodies against vector components were detected in exposed serum. CONCLUSIONS: Arterial collateralization and SBP increased significantly following VEGF vector administration, which was reversed by the Ang-2 vector. Development of antibody against VSV G can limit repeated injections of vector. Future experiments will involve the addition of other pro-angiogenic factors, repeated vector administration, and alternative routes of vector delivery.     

兔缺血后肢内源性VEGF蛋白表达与侧支形成相关性研究

目的：探索缺血肢体代偿侧支形成过程中内源性ＶＥＧＦ蛋白表达的相应规律。方法：新西兰雄性白兔４０只,切除兔一侧后肢股浅动脉全长建立缺血模型,分为１天、３天、７天、１４天、２８天、５６天及９０天７个观察期（ｎ＝５）;另设对照组（ｎ＝５）。观察造模后小腿动脉压比率、动脉造影血管计数及缺血后肢肌组织毛细血管密度和内源性ＶＥＧＦ蛋白的变化。结果：造模后３天,缺血后肢骨骼肌中即有内源性ＶＥＧＦ蛋白表达,７天时达到高峰,２８天后逐渐减弱,而缺血区新血管发生也相应停滞。结论：内源性ＶＥＧＦ蛋白表达有其特定时限性,提示在其表达水平开始下降时,应考虑补充外源性ＶＥＧＦ。     

Vascular endothelial growth factor gene delivery by magnetic DNA nanospheres ameliorates limb ischemia in rabbits

BACKGROUND: Critical limb ischemia often leads to disability and limb loss. Vascular endothelial growth factor (VEGF), delivered either as recombinant protein or as gene therapy, has been shown to promote arteriogenesis and angiogenesis in animal models of limb ischemia. However, most of the studies used a nonspecific targeting system. MATERIALS AND METHODS: Magnetic DNA nanospheres containing expression plasmids encoding VEGF were synthesized, and their morphology, magnetropism, and stability were analyzed. The magnetic DNA nanospheres were administrated via an artery into a rabbit limb ischemia model. The expression of VEGF and vascularization were examined by immunohistochemistry. The angiography was taken to evaluate arteriogenesis. RESULTS: Magnetic DNA nanospheres were very stable and showed a high magnetropism. Gene delivery of such nanospheres via artery under a magnetic field led to the overexpression of VEGF in situ. The capillary density and capillary to muscle fiber ratio were doubled compared with those of the control animals. The arteriogenesis also was promoted in VEGF gene therapy group compared with controls but at later interval than capillary angiogenesis. CONCLUSIONS: Our results suggest that intra-arterial VEGF gene delivery by magnetic DNA nanosphere promotes angiogenesis and arteriogenesis and presents a potent therapeutic strategy for critical limb ischemia.