Cell-synthesized Thread-based Tissue Engineering

基于细胞合成线程的组织工程

• 批准号: 8330796
• 负责人: Nicolas L'Heureux
• 金额: $ 70.52万
• 依托单位: CYTOGRAFT TISSUE ENGINEERING, INC.
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-06 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8330796
• 关键词: Achievement; Affect; Allogenic; Angioplasty; Animal Model; Animals; Arteries; Autologous; Biocompatible Materials; Biological; Blood Vessels; Bone Marrow; Budgets; Bypass; Caliber; Canis familiaris; Cardiovascular Diseases; Cattle; Cause of Death; Cells; Clinical; Clinical Trials; Collagen; Coronary; Coronary Artery Bypass; Crowding; Culture Media; Custom; Data; Deposition; Developed Countries; Development; Devices; Dextrans; Diabetes Mellitus; Disease Progression; Endothelial Cells; Endothelium; Engineering; Extracellular Matrix; Failure; Ficoll; Goals; Grant; Harvest; Hemodialysis; Hemostatic function; Heparin; Human; In Vitro; Incidence; Inflammation; Lead; Legal patent; Lower Extremity; Maintenance; Marketing; Mechanics; Medicare; Modeling; Molecular; Needles; Obesity; Operating Rooms; Operative Surgical Procedures; Patients; Performance; Peripheral; Peripheral arterial disease; Permeability; Phase; Physiologic arteriovenous anastomosis; Procedures; Production; Property; Protocols documentation; Public Health; Puncture procedure; Reporting; Reproducibility; Research; Seeds; Seminal; Serum; Serum-Free Culture Media; Shunt Device; Sterilization; Surface; Systemic disease; Techniques; Testing; Time; Tissue Engineering; Tissues; Transplanted tissue; Tube; Vascular Graft; Veins; Work; aging population; base; clinically relevant; commercialization; cost; cost effective; cost effectiveness; dacron; density; design; dextran; immunogenic; implantation; improved; in vitro testing; in vivo; manufacturing process; meetings; morphometry; novel; novel strategies; pressure; scaffold; self assembly

DESCRIPTION (provided by applicant): Cardiovascular disease is the leading cause of death in industrialized nations. While interventional techniques such as angioplasty and/or stenting can often delay the need for coronary arterial bypass surgery (CABG), long-term efficacy still favors revascularization. Still today, 450,000 coronary bypasses are performed annually in the U.S. alone. Moreover, the number of revascularization procedures for peripheral arterial disease or hemodialysis access is increasing dramatically. Today, 400,000 hemodialysis patients in the U.S. need a patent vascular graft to survive. Creation and maintenance of hemodialysis access grafts takes up nearly 2% of Medicare's entire budget. In addition, population aging and increasing incidence of diabetes and obesity indicate that this is a major public health concern. A patient's own blood vessels clearly remain the best conduits for both coronary and peripheral bypass, as well as for hemodialysis access. Unfortunately, native vein or artery may not be available due to previous harvest or systemic disease progression. Indeed, the primary limitation to arterial revascularization is the availability of suitable native graft material. While synthetic blood vessels made from materials such as Dacron or expanded polytetraflouroethylene (ePTFE) perform well in large diameter applications, these synthetic conduits show unacceptably high failure rates in small diameter applications. We have recently reported excellent clinical trials results with a completely biological human vascular graft built in vitro using a self-assembly approach termed "Sheet-Based Tissue Engineering" (SBTE). However, a significant drawback of this self-assembly approach is the long production time. Here, we propose the development of a novel assembly strategy, called "Thread-Based Tissue Engineering" (TBTE). This novel approach offers the same advantages of a completely biological human product but will dramatically reduce the production time and cost. Combined with an allogeneic and/or devitalization approach, TBTE could finally make completely biological human vascular grafts available "off-the-shelf" and commercially much more competitive. In Phase I of this project, we demonstrated our ability to create threads of various strengths and sizes from both clinically relevant human cells and from canine cells. These threads were then woven into tubes on a custom circular loom to create human and canine vascular grafts. These grafts displayed promising mechanical properties in vitro. Phase I culminated in a short-term in vivo study that demonstrated the very promising clinical potential of human and canine grafts. These results met and exceeded all milestones set forth in the Phase I proposal. In Specific Aim 1 of Phase II, we will finalize the graft design based on promising data obtained in Phase I. These efforts will lead to six designs that will be tested in vivo in Specific Aim 2. Groups of four canines will receive H7 cm x 4.2 mm unendothelialized, devitalized grafts as arteriovenous shunts (femoral-to-femoral). The six designs will be: 1) Autologous, 2) Allogeneic, 3) Allogeneic decellularized, 4) Allogeneic gamma- sterilized, 5) Allogeneic seeded with autologous bone marrow in the operating room, 6) Allogeneic, punctured 3 times weekly with a 16Ga hemodialysis needle after a 3 month post-implantation maturation period. These groups cover the following cost-effectiveness range: 1<<5<<3<2<4. By comparing the performance of these groups, we can determine which design offers the best combination of efficacy and cost. Group 6 will give a first glimpse at the potential of this new type of graft to serve as a hemodialysis access graft. Finally, In Specific Aim 3, we will explore important parameters for the long-term commercialization of these grafts. We will study the use of serum-free medium to produce threads, which would improve reproducibility, reduce cost and simplify regulatory acceptance of the grafts (compared to bovine serum-containing medium). We will also study the use of "molecular crowding" additives to the culture medium. These large molecules have the potential to double or triple collagen assembly and hence, reduce production time and cost. Finally, we will determine if we can seed an endothelium on the woven grafts. While endothelium is not critical in high-flow applications like hemodialysis access grafts, it will be for other important markets/indications like coronary or lower limb bypass. However, establishing an autologous endothelium (allogeneic endothelium are highly immunogenic) introduces significant additional costs. As a cost-effective alternative, we will explore the possibility of replacing it by a new type of heparin coating. This Phase II project will provide: 1) the most cost-effective yet efficacious graft design; 2) initial in vivo efficacy data to justify a more extensive in vivo study to support and IND-submission; 3) additional data to further improve the grafts commercial and regulatory prospects.

描述（由申请人提供）：心血管疾病是工业化国家的主要死亡原因。虽然介入技术如血管成形术和/或支架植入术通常可以延迟冠状动脉旁路手术（CABG）的需要，但长期疗效仍然有利于血运重建。直到今天，仅在美国每年就有45万例冠状动脉搭桥手术。此外，外周动脉疾病或血液透析通路的血运重建手术的数量正在急剧增加。今天，美国有40万血液透析患者需要一个专利的血管移植物才能生存。血液透析通路移植物的创建和维护占据了医疗保险全部预算的近2%。此外，人口老龄化以及糖尿病和肥胖症发病率的增加表明，这是一个重大的公共卫生问题。 患者自身的血管显然仍然是冠状动脉和外周血管搭桥以及血液透析通路的最佳管道。不幸的是，由于之前的采集或全身疾病进展，可能无法获得自体静脉或动脉。事实上，动脉血运重建的主要限制是合适的天然移植材料的可用性。虽然由诸如涤纶或膨胀聚四氟乙烯（ePTFE）的材料制成的合成血管在大直径应用中表现良好，但这些合成导管在小直径应用中显示出不可接受的高故障率。我们最近报道了使用称为“基于片材的组织工程”（SBTE）的自组装方法在体外构建完全生物化的人体血管移植物的出色临床试验结果。然而，这种自组装方法的一个显著缺点是生产时间长。在这里，我们提出了一种新的组装策略，称为“线程为基础的组织工程”（TBTE）的发展。这种新方法提供了完全生物人类产品的相同优点，但将大大减少生产时间和成本。结合同种异体和/或失活方法，TBTE最终可以使完全生物的人类血管移植物“现成”可用，并且在商业上更具竞争力。 在该项目的第一阶段，我们展示了我们从临床相关的人类细胞和犬细胞中创建各种强度和大小的线程的能力。然后，这些线在定制的圆形织机上编织成管，以创建人类和犬的血管移植物。这些移植物在体外表现出良好的机械性能。第一阶段在短期体内研究中达到高潮，该研究证明了人类和犬移植物非常有前途的临床潜力。这些结果达到并超过了第一阶段提案中规定的所有里程碑。 在II期的具体目标1中，我们将根据I期获得的有希望的数据最终确定移植物设计。 这些努力将产生六种设计，这些设计将在Specific Aim 2中进行体内测试。每组4只犬将接受H7 cm x 4.2 mm未内皮化、灭活移植物作为动静脉分流（股-股）。 这六个设计将是：1）自体骨髓，2）同种异体，3）脱细胞的同种异体，4）伽马灭菌的同种异体，5）在手术室中用自体骨髓接种的同种异体，6）同种异体，在3个月的植入后成熟期后，用16 Ga血液透析针每周穿刺3次。这些小组涵盖以下成本效益范围：1<<5<<3<2<4。通过比较这些组的性能，我们可以确定哪种设计提供了功效和成本的最佳组合。第6组将首次介绍这种新型移植物作为血液透析通路移植物的潜力。最后，在具体目标3中，我们将探索这些移植物长期商业化的重要参数。我们将研究使用无血清培养基生产线，这将提高再现性，降低成本，简化移植物的监管验收（与含牛血清培养基相比）。我们还将研究在培养基中使用“分子拥挤”添加剂。这些大分子具有使胶原蛋白组装成两倍或三倍的潜力，从而减少生产时间和成本。最后，我们将确定是否可以在编织移植物上种植内皮细胞。虽然内皮在血液透析通路移植物等高流量应用中并不重要，但它将用于其他重要市场/适应症，如冠状动脉或下肢搭桥术。然而，建立自体内皮（同种异体内皮具有高度免疫原性）引入了显著的额外成本。作为一种具有成本效益的替代方案，我们将探索用新型肝素涂层替代它的可能性。 该II期项目将提供：1）最具成本效益且有效的移植物设计; 2）初始体内有效性数据，以证明更广泛的体内研究的合理性，以支持和IND提交; 3）进一步改善移植物商业和监管前景的额外数据。