Terminal Sterilization of Tendon Allografts with C02

描述（由申请人提供）：医疗器械要求的同种异体肌腱移植的最终灭菌目前几乎不存在。使用环氧乙烷气体的终末灭菌会留下有毒残留物，并对ACL手术后阳性结果的概率产生负面影响。伽玛辐射用于对移植物进行灭菌，但当辐照水平足以达到灭菌时，肌腱就无法使用，因为胶原束和变性蛋白质的分离会导致移植物明显变弱。对肌腱同种异体移植材料进行灭菌的理想方法是一种终末、无毒、保留同种异体移植材料的基本特性，并经过验证达到10-6级的无菌保证水平（与医疗器械要求的水平相同）。我们的初步实验表明，超临界CO2灭菌工艺是解决同种异体肌腱移植材料最终灭菌迫切需要的可行解决方案。我们请求支持开发一种有效的利用超临界CO2的同种异体肌腱移植的终端灭菌过程。本提案的具体目的是：(1)开发一种用超临界二氧化碳对肌腱组织进行终末灭菌的程序；(2)分析灭菌后肌腱组织样本潜在的生物力学变化，并与未处理的进行比较。该项目的长期目标是开发一种商业上可行的终端灭菌方法，该方法将与人体软组织兼容，并最终将终端灭菌成分添加到当前组织库实践中。II期研究将包括综合测试，以验证肌腱中病毒和真菌污染的失活，以及使用动物模型进行测试，以评估超临界CO2灭菌的同种异体移植肌腱在移植物坏死、血运重建、成纤维细胞侵袭和胶原合成等阶段的组织学和生物力学变化。此外，这项技术可以扩展到其他组织中使用，在这些组织中供体细胞的活力是不受关注的。

DESCRIPTION (provided by applicant): Terminal sterilization of tendon allografts to the same levels called for in medical devices is currently all but non-existent. Terminal sterilization using ethylene oxide gas leaves toxic residues and negatively impacts the probability of positive outcomes following ACL surgeries. Gamma irradiation is used to sterilize grafts but at the irradiation levels sufficient to achieve sterilization the tendon is rendered unusable because separation of collagen bundles and denatured proteins result in significant weakening of the graft. An ideal method for sterilization of tendon allograft material would be one that is terminal, non-toxic, retains the essential properties of the allograft, and is validated to achieve sterility assurance level of 10-6 (the same level required for medical devices). Our preliminary experiments indicate that sterilization by our supercritical CO2 process represents a viable solution to answer the pressing need to terminally sterilize tendon allograft material. We request support to develop a validated terminal sterilization process for tendon allografts utilizing supercritical CO2. The specific aims of this proposal are (1) To develop a procedure for terminal sterilization of tendon tissues with supercritical carbon dioxide; (2) To analyze post-sterilization tendon tissue samples for potential biomechanical alterations and compare them with untreated. The long-term objective of this project is to develop a commercially viable terminal sterilization method that would be compatible with human soft tissues and would eventually add a terminal sterilization component to current tissue bank practices. Phase II studies will consist of comprehensive testing to verify inactivation of viral and fungal contaminates in tendon as well as tests using animal models to evaluate histological and biomechanical changes in supercritical CO2 sterilized implanted allograft tendons through the phases of graft necrosis, revascularization, fibroblast invasion and collagen synthesis. Furthermore this technology may be expanded for use in other tissues where donor cell viability is not a concern.