Treatment of venous ulcers with autologous cultured bone marrow stem cells

描述（由申请人提供）：下肢静脉溃疡和其他严重慢性伤口影响500 - 700万美国人，每年造成至少200亿美元的直接费用。静脉溃疡患者的生活质量差，经常感染，失去工作和独立性。近年来，由于更好的传统护理和新的先进疗法，如使用活的生物工程皮肤，临床结果有所改善。然而，静脉高血压的潜在问题导致严重的继发性变化，如组织纤维化、感染倾向以及越来越多地认识到的损害真皮修复和表皮表面重建的驻留伤口细胞中的一组表型变化。静脉溃疡可能变得非常难以愈合。事实上，即使是先进的治疗方法，也不能治愈超过一年的静脉溃疡的50%。 我们最近发现的证据表明，局部应用自体骨髓源性间充质干细胞（MSC），从患者自己的骨髓穿刺液中生长并在体外培养和扩增，可以导致慢性伤口愈合的显着加速，包括静脉溃疡。在我们的前期工作中，我们已经开发了一种新的纤维蛋白聚合物结构，用于在喷雾系统中将培养的MSC递送到伤口。在此过程中，我们通过降低聚合所需的纤维蛋白原/凝血酶浓度和消除作为蛋白酶抑制剂组分的抑肽酶来修改现有的纤维蛋白胶结构。一旦喷洒到伤口中，MSC处于薄的纤维蛋白凝胶中，其不影响其活力并且被内源性消除，从而将细胞释放到伤口。我们现在准备进行一项临床试验，以测试患者自己的MSC可以加速伤口愈合的假设。我们已经开发了一个GMP设施来处理MSC的生长，我们已经收到了来自FDA的IND用于我们的临床试验。我们计划以下两个具体目标：1）在三臂随机对照盲法临床试验中确定MSC对静脉溃疡愈合的影响。所有患者将使用传统腿部压迫绷带进行治疗。将培养的自体MSC以纤维蛋白喷雾剂的形式递送至伤口，并且将该组与仅接受腿部压迫治疗或仅接受纤维蛋白喷雾剂的对照患者进行比较。将通过计算机化平面测量法评估伤口边缘迁移和愈合率、伤口尺寸减小和完全闭合的愈合; 2）表征受损愈合和上皮迁移的伤口边缘分子标志物的表达并使其与治疗反应密切相关。在特定目标1中治疗的静脉溃疡边缘的基线和连续活检将用于确定伤口边缘的c-myc、2-连环蛋白和角蛋白6/16和17的表皮表达。这些测量与伤口大小和边缘迁移密切相关，将帮助我们建立有前途的分子标记物，参与受损的愈合，以及MSC是否可以通过影响这些特定分子标记物的表达和定位来发挥作用。

DESCRIPTION (provided by applicant): Venous leg ulcers and other severe chronic wounds affect 5-7 million Americans, and are responsible for a direct cost of at least $20 billion annually. Patients with venous ulcers experience poor quality of life, frequent infections, and loss of work and independence. Clinical outcomes have improved in recent years because of better conventional care and new advanced therapies, such as the use of living bioengineered skin. However, the underlying problem of venous hypertension leads to severe secondary changes, such as tissue fibrosis, propensity for infection, and an increasingly recognized set of phenotypic changes in resident wound cells that impair dermal repair and epidermal resurfacing. Venous ulcers can become very difficult to heal. Indeed, even advanced therapies heal less than 50% of venous ulcers that have been present for more than a year. We have recently developed evidence that the topical application of autologous bone marrow-derived mesenchymal stem cells (MSCs), grown from the patients' own bone marrow aspirate and cultured and expanded in vitro, can lead to dramatic acceleration of healing in chronic wounds, including venous ulcers. During our preliminary work, we have developed a novel fibrin polymer construct for delivering the cultured MSCs to the wound in a spray system. In doing so, we modified an existing fibrin glue construct by decreasing the fibrinogen/thrombin concentrations required for polymerization and by eliminating aprotenin as the protease inhibitor component. Once sprayed into the wound, the MSCs are in a thin fibrin gel that does not affect their viability and is endogenously eliminated, thus releasing the cells to the wound. We are now ready to move forward with a clinical trial that will test the hypothesis that the patients' own MSCs can accelerate the healing of their wounds. We have developed a GMP facility for handling the the growth of MSCs, and we have received an IND from the FDA for our clinical trial. We plan the following two specific aims: 1) Determine the effect of MSCs on the healing of venous ulcers in a three-arm randomized controlled blinded clinical trial. All patients will be treated with conventional leg compression bandages. Cultured autologous MSCs will be delivered to the wound in a fibrin spray, and this group will be compared to control patients receiving leg compression treatment alone or the fibrin spray only. Healing will be assessed by computerized planimetry for wound edge migration and healing rate, wound size reduction, and complete closure; 2) Characterize and closely correlate the expression of wound edge molecular markers of impaired healing and epithelial migration in response to treatment. Baseline and sequential biopsies from the edges of venous ulcers treated in specific aim 1 will be used to determine the epidermal expression of c-myc, 2-catenin, and keratins 6/16 and 17 at the wounds' edges. These measurements, closely correlated with wound size and edge migration, will help us establish promising molecular markers involved in impaired healing and whether the MSCs may work by affecting the expression and localization of these specific molecular markers.