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(申请人提供)：心血管疾病是工业化国家的主要死亡原因。虽然血管成形术和/或支架植入等介入性技术通常可以推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。尽管如此，仅在美国，每年就有45万例冠状动脉搭桥术。此外，外周动脉疾病或血液透析途径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专利血管移植才能存活。创建和维护血液透析通路移植物占联邦医疗保险整个预算的近2%。此外，人口老龄化和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。患者自己的血管显然仍然是冠脉和外周搭桥以及血液透析通道的最佳通道。不幸的是，由于以前的收获或系统性疾病的进展，可能无法获得天然静脉或动脉。事实上，动脉血运重建的主要限制是合适的国产移植物材料的可用性。虽然由涤纶或发泡聚四氟乙烯(EPTFE)等材料制成的合成血管在大口径应用中表现良好，但这些合成管道在小直径应用中显示出不可接受的高失败率。我们最近报道了一种完全生物的人体血管移植物的良好临床试验结果，该移植物是使用一种名为“基于薄片的组织工程”(SBTE)的自组装方法在体外建立的。然而，这种自组装方法的一个显著缺点是生产时间较长。在这里，我们提出了一种新的组装策略，称为基于线程的组织工程(TBTE)。这种新的方法提供了与完全生物人类产品相同的优点，但将极大地减少生产时间和成本。与同种异体和/或失活方法相结合，TBTE最终可能使完全生物的人类血管移植物变得“现成”，并在商业上更具竞争力。在这个项目的第一阶段，我们展示了我们能够从临床相关的人类细胞和狗的细胞中创造出不同强度和大小的线。然后，这些线在定制的圆形织布机上被编织成管子，以创造出人类和狗的血管移植物。这些移植物在体外表现出良好的力学性能。第一阶段在一项短期的活体研究中达到顶峰，该研究证明了人和狗移植的非常有前途的临床潜力。这些成果达到并超过了第一阶段提案中规定的所有里程碑。在第二阶段的具体目标1中，我们将根据在第一阶段获得的有希望的数据最终完成移植物设计。这些努力将导致六个设计，这些设计将在特定的目标2中进行体内测试。四只犬将接受H7 cm x 4.2 mm无内皮灭活的移植物作为动静脉分流术(股到股)。这六种设计是：1)自体，2)同种异体，3)异体脱细胞，4)同种异体伽玛灭菌，5)同种异体在手术室种植自体骨髓，6)同种异体，植入成熟期3个月后每周用16Ga型血液透析针穿刺术3次。通过比较这些组的性能，我们可以确定哪种设计提供了最佳的疗效和成本组合。第6组将首次展示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来生产丝线，这将提高重复性，降低成本，并简化对移植物的监管接受(与含牛血清的培养基相比)。我们还将研究在培养基中使用“分子拥挤”添加剂。这些大分子有可能使胶原蛋白的组装增加一倍或三倍，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。虽然内皮细胞在血液透析通路移植物等高流量应用中不是关键，但它将用于其他重要的市场/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)会带来显著的额外成本。作为一种经济有效的替代方案，我们将探索用一种新型肝素涂层取代它的可能性。该第二阶段项目将提供：1)最具成本效益和最有效的移植物设计；2)初步的体内疗效数据，以证明更广泛的体内研究支持和IND提交；3)额外的数据，以进一步改善移植物的商业和监管前景。