Terminal Sterilization of Tendon Allografts with C02

描述（由申请人提供）：目前，肌腱同种异体移植物的最终灭菌达到医疗器械要求的相同水平几乎不存在。使用环氧乙烷气体的最终灭菌会留下有毒残留物，并对ACL手术后的积极结局概率产生负面影响。伽马辐照用于对移植物进行灭菌，但在足以实现灭菌的辐照水平下，肌腱变得不可用，因为胶原束和变性蛋白质的分离导致移植物显著弱化。肌腱同种异体移植物材料的理想灭菌方法是最终的、无毒的、保留同种异体移植物的基本特性的方法，并且经确认可达到10-6的无菌保证水平（与医疗器械所需的水平相同）。我们的初步实验表明，我们的超临界CO2灭菌过程代表了一个可行的解决方案，以回答迫切需要最终消毒肌腱同种异体移植材料。我们请求支持开发一种利用超临界CO2的肌腱同种异体移植物的经确认的最终灭菌过程。本提案的具体目的是（1）开发一种使用超临界二氧化碳对肌腱组织进行最终灭菌的程序;（2）分析灭菌后肌腱组织样本的潜在生物力学变化，并将其与未处理的肌腱组织样本进行比较。本项目的长期目标是开发一种商业上可行的最终灭菌方法，该方法将与人体软组织兼容，并最终将在当前组织库实践中添加最终灭菌组件。II期研究将包括验证肌腱中病毒和真菌污染物灭活的综合试验，以及使用动物模型评价超临界CO2灭菌植入同种异体肌腱在移植物坏死、血运重建、成纤维细胞浸润和胶原合成阶段的组织学和生物力学变化的试验。此外，该技术可以扩展用于供体细胞活力不受关注的其他组织。

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.