Name: implantation of electrospun vascular grafts with optimized structure in a rat model
Uploaded: 2018-06-27T13:00:00.000+00:00
Duration: 8 min 46 s
Description: Watch this Scientific Journal Video about Implantation of Electrospun Vascular Grafts with Optimized Structure in a Rat Model at JoVE.com

这项工作得到了自然科学基金项目 (81522023、81530059、91639113、81772000、81371699和 81401534) 的财政支持。

实验动物的使用由南开大学动物实验伦理委员会批准, 并按照《实验室动物护理和使用指南》进行。
1. 静电纺丝 PCL 移植物的制备
注: 本文采用静电纺丝技术制备血管移植。
<ol><li>制备 25 wt% 和 10 wt% 的 pcl 溶液, 分别在甲醇和氯仿混合物中溶解 pcl (1:5 体积比), 室温 (RT) 为12小时。</li>
	<li>将 PCL 溶液装入10毫升的玻璃注射器中。</li>
	<li>把注射器放在21克的针头上。</li>
	<li>将不锈钢芯轴 (直径2毫米, 长度25厘米) 放在收集仪器上。</li>
	<li>对于较厚的纤维移植, 使用 25 wt% 的 PCL 溶液, 从针尖到收集器17厘米的工作距离, 8 毫升/小时的流量, 以及11伏的电压作为静电纺丝参数。对于薄纤维移植, 使用 10 wt% 的 PCL 溶液, 从针尖到收集器的工作距离为20厘米, 流速为2毫升/小时, 电压为18伏, 静电纺丝参数。</li>
	<li>确保所获得的移植物被放置在真空过夜, 以消除残留溶剂。在手术前消毒所有器械, 并保持无菌技术。</li>
	<li>植入前, 通过浸泡10毫升75% 乙醇30分钟, 然后在一夜之间将其暴露在紫外线照射下, 对移植物进行消毒。</li>
	<li>纤维和孔径测量: 使用基于扫描电子显微镜 (SEM) 图像的 ImageJ 软件计算平均光纤直径。</li>
	<li>脚手架机械试验:<ol>
<li>用剃刀刀片将管状支架切成3毫米的长度段。用千分尺测量脚手架的厚度。</li>
		<li>将管状脚手架放在拉力试验机上, 负载能力为 100 N。</li>
		<li>夹紧支架与1毫米之间的钳位距离和拉纵向以10毫米/分钟的速度, 直到破裂。测量断裂时的抗拉强度和极限伸长率。从应力-应变曲线的初始线性区域 (最多5% 个应变) 计算杨氏模量。</li>
	</ol>
</li>
</ol>2. 大鼠腹主动脉植入模型
注意: 手术中使用的所有材料和仪器都是无菌的。在手术过程中, 确保操作者佩戴纱布面罩和无菌手套以避免感染。确保室温保持在 27-30 摄氏度, 以保持动物体温。遵循当地的 IACUC 指南, 关于镇痛。
<ol><li>用雄性大大鼠重 240-270 克作为血管移植的接受者。确保大鼠在手术前禁食24小时。禁食大鼠24小时的目的是充分清空肠道内的粪便, 从而拓宽操作者的视野。</li>
	<li>抓住大鼠的后颈, 把头向下, 将 springe 针插入下腹部的腹腔。用腹腔注射水合氯醛 (330 毫克/千克) 诱导大鼠麻醉。</li>
	<li>确认足够的麻醉, 确保老鼠放松肌肉和稳定呼吸。将老鼠放在手术显微镜下仰卧位。</li>
	<li>将凡士林眼科兽医软膏涂抹于眼部, 以防麻醉时干燥。使用血气生理盐水 (50 界面/毫升) 进行抗凝治疗 (100 ui/千克), 术前采用尾静脉注射。</li>
	<li>用剃刀刀片刮掉前腹壁上的皮毛, 用碘溶液和医疗酒精溶液清洁皮肤。</li>
	<li>用手术剪刀进行中线开腹切口, 确保切口长约 4-5 厘米, 然后暴露腹腔。</li>
	<li>优先用含盐水的纱布缩回和包裹肠道。</li>
	<li>仔细解剖腹主动脉。</li>
	<li>使用9-0 单丝尼龙缝线识别和结扎所有小枝。</li>
	<li>用两个血管钳夹住主动脉的隔离段 (长度可达1厘米)。主动脉可保持钳位20-30 分钟。</li>
	<li>用微型剪刀将腹主动脉与两个夹在一起, 创建吻合点。</li>
	<li>用血气盐水 (50 界面/毫升) 溶液冲洗主动脉的两端, 以去除残余血液。</li>
	<li>用微剪刀剥掉膜。</li>
	<li>吻合2毫米内径和1厘米长到大鼠腹主动脉的移植, 用9-0 单丝尼龙缝合线的八个缝合模式。</li>
	<li>首先, 根据近侧9、3、12和6点位置的顺序构造四吻合口, 然后在两条缝线之间吻合4针的切口边缘。完成近端缝合后, 用同一方法缝合远端。 注: 每针都需要确保本机侧是轻微嵌入在嫁接。</li>
	<li>取出远端钳, 让血液流入移植物, 然后取出近端钳。</li>
	<li>按缝合末端以停止使用无菌棉球或小纱布海绵止血。按压大约3分钟, 直到止血。</li>
	<li>把肠子放回腹腔。</li>
	<li>用庆大霉素 (320 U/毫升) 温热生理盐水溶液冲洗腹腔。</li>
	<li>用3-0 尼龙缝合在肌肉和皮肤层缝上腹壁, 分别。</li>
	<li>把老鼠放进干净干燥的笼子里, 在笼子下面放一个暖气垫, 保持动物体温;然后等待老鼠从麻醉中恢复。注意动物, 直到它恢复了足够的意识来维持胸骨卧床。</li>
	<li>在它恢复知觉之后, 把老鼠放进一个笼子里, 里面有食物和水。在伤口上涂上碘, 以防手术后感染。把老鼠送到其他动物的公司, 直到它完全恢复。</li>
	<li>弄死大鼠根据机构指南在预定的时间点。</li>
</ol>

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作者没有相互矛盾的经济利益。

细胞浸润对16体内血管移植的再生和重塑至关重要。有限细胞浸润通常与移植的相对较小的毛孔有关, 阻碍细胞向移植壁迁移。为了解决这一困难, 我们开发了一种改进的方法来制备静电纺丝 PCL 血管移植的大孔结构。详细地说, 孔隙大小随纤维厚度的增加而增大, 其加工参数可以很容易地控制。结果表明,在体外植入后, 宿主细胞很容易渗入到大孔移植的壁内, 细胞构?...

合成高分子的血管移植广泛应用于心血管疾病 (心血管病) 的临床治疗。不幸的是, 在小直径血管移植 (D < 6 毫米) 的情况下, 没有成功的产品, 由于低通畅触发的血液流速降低, 这往往导致血栓形成, 内膜增生, 和其他并发症1。
组织工程提供了一个替代策略, 以实现长期通畅和动态平衡的基础上的支架引导血管再生和重建。详细来说, 血管移植作为一个三维模板, 可以在血管组织再生过程中提供机械支持和结构指导, 并影响细胞功能, 包括细胞黏附、迁移、增殖和分泌细胞外基质2。到目前为止, 各种合成聚合物已被评价为应用于血管组织工程。在这些聚合物中, 聚 (己内酯) (PCL) 由于良好的细胞相容性和缓慢的降解, 从几个月到两年不等, 已被深入研究。用静电纺丝处理的大鼠主动脉模型4、5、6、PCL 血管移植表现出优良的结构完整性和通畅性, 并不断增加细胞侵袭和新生血管移植壁长达6月。然而, 不良组织重塑, 包括细胞的回归和毛细血管和钙化, 也被观察到更长的 timepoints, 长达18月。
Cellularization 血管移植是决定组织再生和重塑7的关键因素。静电纺丝作为一种多功能技术, 已广泛应用于纳米纤维结构8的血管移植的制备。不幸的是, 相对较小的孔隙结构往往导致细胞浸润不足的静电纺丝血管移植, 这限制了随后的组织再生。为了解决这一问题, 尝试了各种技术来提高孔径和整体孔隙率, 包括盐/聚合物浸出9,10, 集热器的修改, 激光辐照后处理11等。事实上, 静电纺丝的结构 (包括纤维直径、孔隙大小和孔隙度) 与加工条件12、13密切相关。在静电纺丝过程中, 通过改变聚合物溶液的浓度、流量、电压等参数, 可以很容易地控制纤维的直径. 14,15, 因此, 孔隙大小和孔隙度得到了相应的增强。
我们最近报告了一个改良的 PCL 静电纺丝移植与大孔结构 (纤维直径 5-7 µm 和毛孔 30-40 µm)。在活体移植中, 取代大鼠腹主动脉显示出高的通畅率, 以及良好的内皮化和平滑肌再生3月后手术16。更重要的是, 即使在植入一年后, 也不会有钙化和细胞回归等不良组织重塑。

<table><tbody><tr><td>Poly(&amp;epsilon;-caprolactone) (PCL) pellets (M&lt;sub&gt;n&lt;/sub&gt;=80,000)</td><td>Sigma</td><td>704067</td><td></td></tr><tr><td>Methanol</td><td>Tianjin Chemical Reagent Company</td><td>1060</td><td></td></tr><tr><td>Alcohol</td><td>Tianjin Chemical Reagent Company</td><td>1083</td><td></td></tr><tr><td>Chloroform</td><td>Tianjin Chemical Reagent Company</td><td>A1007</td><td></td></tr><tr><td>Sucrose</td><td>Tianjin Fengchuan Company</td><td>2296</td><td></td></tr><tr><td>Triton X-100</td><td>Alfa Aesar</td><td>A16046</td><td></td></tr><tr><td>Sprague Dawley rats</td><td>Laboratory Animal Center of the Academy of Military Medical Sciences</td><td></td><td></td></tr><tr><td>Normal saline</td><td>Hebei Tiancheng Pharmaceutical company</td><td></td><td></td></tr><tr><td>Chloral hydrate</td><td>Tianjin Ruijinte chemical company</td><td>2223</td><td></td></tr><tr><td>Heparin sodium Injection</td><td>Tianjin Biochem Pharmaceutical company</td><td></td><td></td></tr><tr><td>Gentamycin Sulfate Injection</td><td>Jiangsu Lianshui Pharmaceutical company</td><td></td><td></td></tr><tr><td>Mouse anti-&amp;alpha;-SMA primary antibody</td><td>Abcam</td><td>ab7817</td><td></td></tr><tr><td>Mouse anti-smooth MYH primary antibody</td><td>Abcam</td><td>ab683</td><td></td></tr><tr><td>Rabbit polyclonal anti-rat elastin antibody</td><td>Abcam</td><td>ab23748</td><td></td></tr><tr><td>Rabbit anti-von Willebrand factor primary antibody</td><td>Abcam</td><td>ab6994</td><td></td></tr><tr><td>Goat anti-mouse IgG (Alexa Fluor 488)</td><td>Invitrogen</td><td>ab150117</td><td></td></tr><tr><td>Goat anti-rabbit IgG (Alexa Fluor 488)</td><td>Invitrogen</td><td>ab150077</td><td></td></tr><tr><td>5% normal goat serum</td><td>Zhongshan Golden bridge</td><td>ZLI9022</td><td></td></tr><tr><td>Hematoxylin and eosin (H&amp;amp;E)</td><td>Beijing leagene biotech</td><td>DH0006</td><td></td></tr><tr><td>Masson&#039;s trichrome</td><td>Beijing leagene biotech</td><td>DC0032</td><td></td></tr><tr><td>Verhoeff-van Gieson (VVG)</td><td>Beijing leagene biotech</td><td>DC0059</td><td></td></tr><tr><td>Von Kossa</td><td>Beijing leagene biotech</td><td>DS0003</td><td></td></tr><tr><td>Surgical sutures needles with thread,3-0 silk</td><td>Shanghai Jinhuan medical supplies company</td><td>G3002b</td><td></td></tr><tr><td>Surgical sutures needles with thread,9-0 silk</td><td>Shanghai Jinhuan medical supplies company</td><td>H901</td><td></td></tr></tbody></table>

implantation of electrospun vascular grafts with optimized structure in a rat model

在这里, 我们提出了一个制备大孔 PCL 血管移植的协议, 并描述了一个模型的应用腹主动脉替代模式的评估协议。静电纺丝血管移植通常具有相对较小的孔隙, 限制细胞浸润到移植物中, 阻碍新动脉的再生和重塑。本研究采用改良的工艺制备了较厚纤维 (5-6 µm) 和较大孔隙 (~ 30 µm) 的 PCL 血管移植。采用大鼠腹主动脉模型植入法对移植物的远期表现进行评价。超声分析显示, 即使植入12月后, 移植物仍未发生动脉瘤或狭窄。大孔结构改善细胞肉芽, 从而促进组织再生3月。更重要的是, 没有出现不良重塑的迹象, 例如12月后移植壁内的钙化。因此, 经改良大孔处理的静电纺丝 PCL 血管移植可作为长期植入的动脉替代物。

对 PCL 移植术后3月和12月说明, 用标准组织学技术对苏木精和伊红 (H & E)、马尾松三色、Verhoeff Gieson (VVG)、冯科萨和α SMA 的免疫荧光染色进行分析,MYH, vWF 和弹力蛋白。组织学图像采用直立显微镜, 用ﬂuorescence 显微镜拍摄免疫荧光图像。
所有数据均以平均值表示。用双尾配对学生的t检验来比较差异。p < 0.05 的值被?...

Watch this Scientific Journal Video about Implantation of Electrospun Vascular Grafts with Optimized Structure in a Rat Model at JoVE.com

Implantation of Electrospun Vascular Grafts with Optimized Structure in a Rat Model

优化结构静电纺丝血管移植在大鼠模型中的植入

在此, 我们提出了一种改进的静电纺丝方法, 以制造粗纤维和大孔隙的 PCL 血管移植, 并描述了一个协议, 以评估在体内的性能在大鼠腹主动脉置换模型。

Here, we present a protocol to fabricate macroporous PCL vascular graft and describe an evaluation protocol by using a rat model of abdominal aorta ...

implantation-electrospun-vascular-grafts-with-optimized-structure-rat

Research

JoVE Journal

Biology

7.9K 次观看.  Nankai University. 在此, 我们提出了一种改进的静电纺丝方法, 以制造粗纤维和大孔隙的 PCL 血管移植, 并描述了一个协议, 以评估在体内的性能在大鼠腹主动脉置换模型。

视频: Implantation of Electrospun Vascular Grafts with Optimized Structure in a Rat Model

Training a Sophisticated Microsurgical Technique: Interposition of External Jugular Vein Graft in the Common Carotid Artery in Rats

Neointimal hyperplasia is one the primary causes of stenosis in arterialized veins that are of great importance in arterial coronary bypass surgery, in peripheral arterial bypass surgery as well as in arteriovenous fistulas.1-5 The experimental procedure of vein graft interposition in the common carotid artery by using the cuff-technique has been applied in several research projects to examine the aetiology of neointimal hyperplasia and therapeutic options to address it. 6-8 The cuff prevents vessel anastomotic remodeling and induces turbulence within the graft and thereby the development of neointimal hyperplasia.
Using the superior caval vein graft is an established small-animal model for venous arterialization experiment.9-11 This current protocol refers to an established jugular vein graft interposition technique first described by Zou et al., 9 as well as others.12-14 Nevertheless, these cited small animal protocols are complicated.
To simplify the procedure and to minimize the number of experimental animals needed, a detailed operation protocol by video training is presented. This video should help the novice surgeon to learn both the cuff-technique and the vein graft interposition. Hereby, the right external jugular vein was grafted in cuff-technique in the common carotid artery of 21 female Sprague Dawley rats categorized in three equal groups that were sacrificed on day 21, 42 and 84, respectively. Notably, no donor animals were needed, because auto-transplantations were performed. The survival rate was 100 % at the time point of sacrifice. In addition, the graft patency rate was 60 % for the first 10 operated animals and 82 % for the remaining 11 animals. The blood flow at the time of sacrifice was 8&plusmn;3 ml/min. In conclusion, this surgical protocol considerably simplifies, optimizes and standardizes this complicated procedure. It gives novice surgeons easy, step-by-step instruction, explaining possible pitfalls, thereby helping them to gain expertise fast and avoid useless sacrifice of experimental animals.

Neointimal hyperplasia is the primary cause of stenosis in arterialized veins. We propose a new protocol whereby the right external jugular vein is grafted using the cuff technique in the common carotid artery of Sprague Dawley rats. The survival rate was 100 % at the time point of sacrifice.

培养一个精密的显微外科技术在大鼠颈总动脉，颈外静脉移植：介入

Neointimal hyperplasia is one the primary causes of stenosis in arterialized veins that are of great importance in arterial coronary bypass surgery, in ...

科研

医学

Implantation of Engineered Tissue in the Rat Heart

Rodent surgery is often an important component in assessing the utility of engineered tissues. A wide variety of surgical procedures can be performed in common laboratory rats or mice and these quite frequently serve as an intermediate step between bench-top experiments and large animal testing or human trials. Given that rodents provide an established, cost-effective, and physiologically-relevant model system in which to test novel combinations of scaffolding materials and cells, they are particularly well-suited for cardiovascular tissue engineering studies. Presently, we describe an open-heart surgical procedure to implant engineered tissue containing myogenic progenitor cells in the atrioventricular (AV) groove of a rat heart. These implants are intended to create an electrical conduit between the right atrium and right ventricle with the ultimate goal of providing an alternative treatment to conventional pacemaker implantation in pediatric patients with complete heart block[1]. The engineered tissue is implanted in the AV-groove by means of a thoracotomy. For our purposes, Lewis rats are anesthetized and invasively ventilated to maintain positive airway pressure during the sterile surgical procedure. The approach to the heart is performed by a right thoracotomy through an antero-lateral incision at the 5th intercostal space. The tissue construct is fixed in the AV groove using a single 7-0 Prolene suture and positioned between the right ventricle and atrium at the ventral portion of the heart. The epicardium is partially removed to allow direct contact between the recipient myocardial cells and those contained in the engineered tissue. Following implantation, the chest wall is closed in layers, any pneumothorax is evacuated, and the animal is extubated and treated with analgesic.

Here, we describe a cardiac surgical procedure to implant engineered tissue in the atrioventricular (AV)-groove of an adult Lewis rat.

大鼠心脏中植入的工程组织

Rodent surgery is often an important component in assessing the utility of engineered tissues. A wide variety of surgical procedures can be performed in ...

生物学

Surgical Technique for the Implantation of Tissue Engineered Vascular Grafts and Subsequent In Vivo Monitoring

The development of Tissue Engineered Vessels (TEVs) is advanced by the ability to routinely and effectively implant TEVs (4-5 mm in diameter) into a large animal model. A step by-step protocol for inter-positional placement of the TEV and real-time digital assessment of the TEV and native carotid arteries is described here. In vivo monitoring is made possible by the implantation of flow probes, catheters and ultrasonic crystals (capable of recording dynamic diameter changes of implanted TEVs and native carotid arteries) at the time of surgery. Once implanted, researchers can calculate arterial blood flow patterns, invasive blood pressure and artery diameter yielding parameters such as pulse wave velocity, augmentation index, pulse pressures and compliance. Data acquisition is accomplished using a single computer program for analysis throughout the duration of the experiment. Such invaluable data provides insight into TEV matrix remodeling, its resemblance to native/sham controls and overall TEV performance in vivo.

Surgical Technique for the Implantation of Tissue Engineered Vascular Grafts and Subsequent In Vivo Monitoring

A step-by-step protocol for the inter-positional placement of Tissue Engineered Vessels (TEVs) into the carotid artery of a sheep using end-to-end anastomosis and real-time digital assessment in vivo until animal sacrifice.

手术技术组织工程血管移植和后续的植入<em&gt;在体内</em&gt;监控

The development of Tissue Engineered Vessels (TEVs) is advanced by the ability to routinely and effectively implant TEVs (4-5 mm in diameter) into a large ...

生物工程

Generation and Grafting of Tissue-engineered Vessels in a Mouse Model

The construction of vascular conduits is a fundamental strategy for surgical repair of damaged and injured vessels resulting from cardiovascular diseases. The current protocol presents an efficient and reproducible strategy in which functional tissue engineered vessel grafts can be generated using partially induced pluripotent stem cell (PiPSC) from human fibroblasts. We designed a decellularized vessel scaffold bioreactor, which closely mimics the matrix protein structure and blood flow that exists within a native vessel, for seeding of PiPSC-endothelial cells or smooth muscle cells prior to grafting into mice. This approach was demonstrated to be advantageous because immune-deficient mice engrafted with the PiPSC-derived grafts presented with markedly increased survival rate 3 weeks after surgery. This protocol represents a valuable tool for regenerative medicine, tissue engineering and potentially patient-specific cell-therapy in the near future.

Here, we present a protocol to generate tissue engineered vessel grafts that are functional for grafting into mice by double seeding partially induced pluripotent stem cell (PiPSC) - derived smooth muscle cells and PiPSC - derived endothelial cells on a decellularized vessel scaffold bioreactor.

组织工程血管在小鼠模型的生成和嫁接

The construction of vascular conduits is a fundamental strategy for surgical repair of damaged and injured vessels resulting from cardiovascular diseases. ...

Athymic Rat Model for Evaluation of Engineered Anterior Cruciate Ligament Grafts

Anterior cruciate ligament (ACL) rupture is a common ligamentous injury that often requires surgery because the ACL does not heal well without intervention. Current treatment strategies include ligament reconstruction with either autograft or allograft, which each have their associated limitations. Thus, there is interest in designing a tissue-engineered graft for use in ACL reconstruction. We describe the fabrication of an electrospun polymer graft for use in ACL tissue engineering. This polycaprolactone graft is biocompatible, biodegradable, porous, and is comprised of aligned fibers. Because an animal model is necessary to evaluate such a graft, this paper describes an intra-articular athymic rat model of ACL reconstruction that can be used to evaluate engineered grafts, including those seeded with xenogeneic cells. Representative histology and biomechanical testing results at 16 weeks postoperatively are presented, with grafts tested immediately post-implantation and contralateral native ACLs serving as controls. The present study provides a reproducible animal model with which to evaluate tissue engineered ACL grafts, and demonstrates the potential of a regenerative medicine approach to treatment of ACL rupture.

Animal models are important tools for the evaluation of tissue-engineered grafts. This paper presents the protocol for preparing an electrospun biodegradable polymer graft for use in anterior cruciate ligament tissue engineering, as well as a surgical protocol for implantation in a rat model.

无胸​​腺大鼠模型工程前交叉韧带移植评估

Anterior cruciate ligament (ACL) rupture is a common ligamentous injury that often requires surgery because the ACL does not heal well without ...

Implantation of Inferior Vena Cava Interposition Graft in Mouse Model

Biodegradable scaffolds seeded with bone marrow mononuclear cells (BMCs) are often used for reconstructive surgery to treat congenital cardiac anomalies. The long-term clinical results showed excellent patency rates, however, with significant incidence of stenosis. To investigate the cellular and molecular mechanisms of vascular neotissue formation and prevent stenosis development in tissue engineered vascular grafts (TEVGs), we developed a mouse model of the graft with approximately 1 mm internal diameter. First, the TEVGs were assembled from biodegradable tubular scaffolds fabricated from a polyglycolic acid nonwoven felt mesh coated with &#949;-caprolactone and L-lactide copolymer. The scaffolds were then placed in a lyophilizer, vacuumed for 24 hr, and stored in a desiccator until cell seeding. Second, bone marrow was collected from donor mice and mononuclear cells were isolated by density gradient centrifugation. Third, approximately one million cells were seeded on a scaffold and incubated O/N. Finally, the seeded scaffolds were then implanted as infrarenal vena cava interposition grafts in C57BL/6 mice. The implanted grafts demonstrated excellent patency (&#62;90%) without evidence of thromboembolic complications or aneurysmal formation. This murine model will aid us in understanding and quantifying the cellular and molecular mechanisms of neotissue formation in the TEVG.

To improve our knowledge of cellular and molecular neotissue formation, a murine model of the TEVG was recently developed. The grafts were implanted as infrarenal vena cava interposition grafts in C57BL/6 mice. This model achieves similar results to those achieved in our clinical investigation, but over a far shortened time-course.

下腔静脉间置移植物在小鼠模型中植入

Biodegradable scaffolds seeded with bone marrow mononuclear cells (BMCs) are often used for reconstructive surgery to treat congenital cardiac anomalies. ...

The Arteriovenous (AV) Loop in a Small Animal Model to Study Angiogenesis and Vascularized Tissue Engineering

A functional blood vessel network is a prerequisite for the survival and growth of almost all tissues and organs in the human body. Moreover, in pathological situations such as cancer, vascularization plays a leading role in disease progression. Consequently, there is a strong need for a standardized and well-characterized in vivo model in order to elucidate the mechanisms of neovascularization and develop different vascularization approaches for tissue engineering and regenerative medicine.
We describe a microsurgical approach for a small animal model for induction of a vascular axis consisting of a vein and artery that are anastomosed to an arteriovenous (AV) loop. The AV loop is transferred to an enclosed implantation chamber to create an isolated microenvironment in vivo, which is connected to the living organism only by means of the vascular axis. Using 3D imaging (MRI, micro-CT) and immunohistology, the growing vasculature can be visualized over time. By implanting different cells, growth factors and matrices, their function in blood vessel network formation can be analyzed without any disturbing influences from the surroundings in a well controllable environment. 
In addition to angiogenesis and antiangiogenesis studies, the AV loop model is also perfectly suited for engineering vascularized tissues. After a certain prevascularization time, the generated tissues can be transplanted into the defect site and microsurgically connected to the local vessels, thereby ensuring immediate blood supply and integration of the engineered tissue. By varying the matrices, cells, growth factors and chamber architecture, it is possible to generate various tissues, which can then be tailored to the individual patient's needs.

The Arteriovenous AV Loop in a Small Animal Model to Study Angiogenesis and Vascularized Tissue Engineering

We describe a microsurgical approach for the generation of an arteriovenous (AV) loop as a model for analyzing vascularization in vivo in an isolated and well-characterized environment. This model is not only useful for the investigation of angiogenesis, but is also optimally suited for engineering axially vascularized and transplantable tissues.

在小型动物模型的动静脉（AV）循环研究血管生成和血管组织工程

A functional blood vessel network is a prerequisite for the survival and growth of almost all tissues and organs in the human body. Moreover, in ...

Tissue-Engineered Graft for Circumferential Esophageal Reconstruction in Rats

The use of biocompatible materials for circumferential esophageal reconstruction is a technically challenging task in rats and requires an optimal implant technique with nutritional support. Recently, there have been many attempts at esophageal tissue engineering, but the success rate has been limited due to difficulty in early epithelization in the special environment of peristalsis. Here, we developed an artificial esophagus that can improve the regeneration of the esophageal mucosa and muscle layers through a two-layered tubular scaffold, a mesenchymal stem cell-based bioreactor system, and a bypass feeding technique with modified gastrostomy. The scaffold is made of polyurethane (PU) nanofibers in a cylindrical shape with a three-dimensional (3D) printed polycaprolactone strand wrapped around the outer wall. Prior to transplantation, human-derived mesenchymal stem cells were seeded into the lumen of the scaffold, and bioreactor cultivation was performed to enhance cellular reactivity. We improved the graft survival rate by applying surgical anastomosis and covering the implanted prosthesis with a thyroid gland flap, followed by temporary nonoral gastrostomy feeding. These grafts were able to recapitulate the findings of initial epithelialization and muscle regeneration around the implanted sites, as demonstrated by histological analysis. In addition, increased elastin fibers and neovascularization were observed in the periphery of the graft. Therefore, this model presents a potential new technique for circumferential esophageal reconstruction.

Esophageal reconstruction is a challenging procedure, and development of a tissue-engineered esophagus that enables regeneration of esophageal mucosa and muscle and that can be implanted as an artificial graft is necessary. Here, we present our protocol to generate an artificial esophagus, including scaffold manufacturing, bioreactor cultivation, and various surgical techniques.

用于大鼠圆周食管重建的组织工程移植

The use of biocompatible materials for circumferential esophageal reconstruction is a technically challenging task in rats and requires an optimal implant ...

Vein Interposition Model: A Suitable Model to Study Bypass Graft Patency

Bypass grafting is an established treatment method for coronary artery disease. Graft patency continues to be the Achilles heel of saphenous vein grafts. Research models for bypass graft failure are essential for a better understanding of pathobiological and pathophysiological processes during graft patency loss. Large animal models, such as pigs or sheep, resemble human anatomical structures but require special facilities and equipment. This video describes a rat vein interposition model to investigate vein graft patency loss. Rats are inexpensive and easy to handle. Compared to mouse models, the convenient size of rats permits better operability and enables a sufficient amount of material to be obtained for further diverse analysis. In brief, the inferior epigastric vein of a donor rat is harvested and used to replace a segment of the femoral artery. Anastomosis is conducted via single stitches and sealed with fibrin glue. Graft patency can be monitored non-invasively using duplex sonography. Myointimal hyperplasia, which is the main cause for graft patency loss, develops progressively over time and can be calculated from histological cross sections.

This video demonstrates a model to study the development of myointimal hyperplasia after venous interposition surgery in rats.

静脉介入型号:研究旁路移植通畅一个合适的模型

Bypass grafting is an established treatment method for coronary artery disease. Graft patency continues to be the Achilles heel of saphenous vein grafts. ...

Implantation of Tissue-Engineered Vascular Graft in Mouse Carotid Artery via Cuff Technique

The development of small-diameter vascular grafts has been a global endeavor, with numerous research groups contributing to this field. Animal experimentation plays a pivotal role in assessing the efficacy and safety of vascular grafts, particularly in the absence of clinical applications. Compared to alternative animal models, the mouse implantation model offers several advantages, including a well-defined genetic background, a mature method for disease model construction, and a straightforward surgical procedure. Based on these advantages, the present study devised a simple cuff technique for the implantation of tissue-engineered vascular grafts in the mouse carotid artery. This technique began with the fabrication of polycaprolactone (PCL) small-diameter vascular grafts via electrostatic spinning, followed by the seeding of macrophages onto the grafts through perfusion adsorption. Subsequently,&#160;the cellularized tissue-engineered vascular grafts were transplanted into the mouse carotid artery using the cuff technique to evaluate patency and regenerative capability. After 30 days of in vivo implantation, vascular patency was found to be satisfactory, with evidence of neo-tissue regeneration and the formation of an endothelial layer within the lumen of the grafts. All data were analyzed using statistical and graphing software. This study successfully established a mouse carotid artery implantation model that can be used to explore the cellular sources of vascular regeneration and the mechanisms of action of active substances. Furthermore, it provides theoretical support for the development of novel small-diameter vascular grafts.

Here, a protocol is presented for the implantation of a tissue-engineered vascular graft into the mouse carotid artery using the cuff technique, providing a suitable animal model for investigating vascular tissue regeneration mechanisms.

优化结构静电纺丝血管移植在大鼠模型中的植入

摘要

探索更多视频

此视频中的章节

培养一个精密的显微外科技术在大鼠颈总动脉，颈外静脉移植：介入

大鼠心脏中植入的工程组织

手术技术组织工程血管移植和后续的植入

组织工程血管在小鼠模型的生成和嫁接

无胸腺大鼠模型工程前交叉韧带移植评估

下腔静脉间置移植物在小鼠模型中植入

在小型动物模型的动静脉（AV）循环研究血管生成和血管组织工程

用于大鼠圆周食管重建的组织工程移植

静脉介入型号:研究旁路移植通畅一个合适的模型

通过 Cuff 技术将组织工程血管移植物植入小鼠颈动脉

优化结构静电纺丝血管移植在大鼠模型中的植入

摘要

探索更多视频

此视频中的章节

培养一个精密的显微外科技术在大鼠颈总动脉，颈外静脉移植：介入

大鼠心脏中植入的工程组织

手术技术组织工程血管移植和后续的植入

组织工程血管在小鼠模型的生成和嫁接

无胸​​腺大鼠模型工程前交叉韧带移植评估

下腔静脉间置移植物在小鼠模型中植入

在小型动物模型的动静脉（AV）循环研究血管生成和血管组织工程

用于大鼠圆周食管重建的组织工程移植

静脉介入型号:研究旁路移植通畅一个合适的模型

通过 Cuff 技术将组织工程血管移植物植入小鼠颈动脉

无胸腺大鼠模型工程前交叉韧带移植评估