基于电子转移的石墨烯基薄膜构建及其生物学效应

Lack of environmental recognition and response capabilities is the technical bottleneck restricting the development of bioactive materials. Electron transfer is an important way for materials to communicate with biological systems. Mastering the behavior of electronic transfer between materials and biological systems is the basis for developing bioactive materials with environmental recognition and response capabilities. In view of this, this work proposes to construct graphene-based films with controllable electron transfer characteristics on the medical titanium surface and use the electron transfer between the graphene-based film and cells / bacteria to realize the identification and response to the physiological environment. Investigate the mechanism of chemical doping on the electronic structure of graphene and realize the preparation of graphene films with controllable electron transfer characteristics. Study the electron transfer process between graphene-based films and cells / bacteria from the molecular and cell levels and elucidate the effect of electron transfer on cell / bacterial behavior and its internal mechanism. Explore the application prospects of graphene films based on electron transfer in antibacterial and tissue repair fields.

缺乏环境识别和响应能力是制约生物活性材料发展的技术瓶颈。电子转移是材料与生物系统“交流”的重要方式，掌握材料与生物系统之间的电子转移行为是开发具有环境识别和响应能力生物活性材料的基础。鉴于此，本课题提出在医用钛表面构建具有可控电子转移特性的石墨烯基薄膜，利用石墨烯基薄膜与细胞/细菌之间的电子转移实现对生理环境的识别和响应。探究化学掺杂对石墨烯电子结构的调控机制，实现具有可控电子转移特性石墨烯薄膜的制备。从分子和细胞水平系统研究石墨烯基薄膜与细胞/细菌之间的电子转移过程，阐明电子转移对细胞/细菌行为的影响规律和内在机理。探索基于电子转移石墨烯薄膜在抗菌和组织修复领域的应用前景。

医用钛及钛合金具有生物相容性好、耐腐蚀性强等优点，因而常被用于外科植入材料。然而，钛及其合金属于生物惰性材料，缺乏环境识别和响应能力。近年来，石墨烯及其衍生物由于其优异的物理化学性能在生物医学领域得到了广泛的关注。因此，本项目提出在医用钛表面构建石墨烯基薄膜，研究石墨烯基薄膜对细胞/细菌行为的影响规律和相关作用机制。在本项目的资助下，团队采用等离子体增强化学气相沉积技术在医用钛表面原位生长垂直石墨烯薄膜，研究发现石墨烯薄膜垂直于钛表面生长，反应温度影响垂直石墨烯的成核，垂直石墨烯表现出疏水的表面，更好的耐腐蚀性，同时展现出很好的光热转换效应和体外体内光热抗菌效果，垂直石墨烯薄膜优异的光热抗菌效应在医用植入材料的表面抗感染领域具有很好的应用前景。此外，团队结合电泳沉积技术和水热处理技术在医用钛表面构建了氧化石墨烯/锌铁层状双氢氧化物复合薄膜（ZnFe-LDH@GO）。ZnFe-LDH@GO薄膜表现出亲水的表面，能够抑制胆管癌细胞的早期粘附和增殖。体内动物实验证实ZnFe-LDH@GO样品能够抑制肿瘤细胞的生长和转移，且对正常组织无明显影响，表现出较佳的肿瘤抑制效果。ZnFe-LDH@GO复合薄膜将为用于人体各种腔道恶性梗阻姑息治疗的钛合金支架表面改性提供新策略，通过抑制肿瘤细胞的粘附和增殖，有望降低再梗阻概率。