骨科植入材料的表面改性研究因其显著的效果以及不影响基底材料的力学性能而具有良好的应用前景。本项目以气体等离子体浸没离子注入(PIII)方法表面改性医用聚四氟乙烯：基于项目负责人对等离子体技术的创新，突破了传统气体PIII处理不导电高分子试样时的参数限制。我们拟采用双重气体的PIII处理对聚四氟乙烯表面形貌及化学组成进行一体化修饰，根据处理过程中实验参数的调整于样品表面构建不同的微纳结构及选择性地引入活性官能团，进而实现对聚四氟乙烯试样表面理化性质的可控调节；同时根据细胞学实验深入评估不同处理后样品，探究材料表面理化性质影响细胞生长分化的可能机理，明确试样表面利于成骨的最优化表面性质。本项目的顺利实施将为高分子生物材料的表面功能化研究和最终的临床应用奠定坚实的基础。

Surface modification of bone implant materials is promising in clinical application on account of the significant effect as well as uncompromising the mechanical properties of bulk materials. In this project, a novel gas plasma immersion ion implantation (PIII) will be applied to biomedical polytetrafluoroethylene, with breakthrough of the parameter limitation when insulative polymer is involved in conventional gas PIII. A dual gas PIII process will be conducted on polytetrafluoroethylene to alter the surface chemistry and topography simultaneously. In particular, by modulating the experimental parameters in sample processing, varied miro-nano structures can be constructed onto polytetrafluoroethylene with optional involvement of active functional groups. Hence, samples with tunable surface physicochemical properties will be attained. The varied processed samples will be further evaluated by cell and animal experiments to determine the optimized physicochemical properties regarding osseointegration, the relationship between sample surface properties and their bio-functions will also be explored in mechanism. As features to this project, surface pH values as well as the dynamic behaviors of live cells on samples will be assessed by utilizing micro pH technique and novel live cell imaging system equipped with upright microscope. The smooth implementation of this project will lay a solid foundation for surface functionalization of polymeric biomaterials and their clinical applications.

以医用聚四氟乙烯(polytetrafluoroethylene, PTFE)材料制备的小口径人工血管由于容易引起血栓和内膜增生而导致其长期通畅率低下，其根本原因在于PTFE材料表面无法形成内皮化并且容易引起慢性炎症反应。因此，研发能够快速实现内皮化、抗血栓形成以及具有低免疫炎症反应的新型血管植入材料具有非常重要的意义。在本项目中，我们首先采用等离子体浸没离子注入(plasma immersion ion implantation, PIII)技术对医用PTFE进行表面改性。经过N2 PIII处理后，医用PTFE不仅能够在表面形成特定的微纳结构，在离子注入发生作用的材料表层区域还生成了大量的活性自由基。这些活性自由基能够不断地迁移至材料表面，进而与外界环境中存在的分子发生进一步的反应。基于此原理，我们通过简单的溶液浸泡方式就能够将不同种类的功能性生物分子稳定地负载在医用PTFE表面。研究结果表明，肝素、SDF-1α 和CD47这三种功能性生物分子都能够在保持生物活性的同时以共价接枝的方式固定在经N2 PIII处理的医用PTFE表面。经功能化改性后的PTFE试样同时具有抗血栓生成、募集内皮祖细胞以及减轻机体炎症反应等多重表面功能，因此是一种理想的血管植入材料可用于制备具有良好长期通畅率的小口径人工血管。