Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras , Chennai 600036, India.
ACS Appl Mater Interfaces. 2017 Feb 8;9(5):4498-4508. doi: 10.1021/acsami.6b14863. Epub 2017 Jan 30.
Surface engineering of implantable devices involving polymeric biomaterials has become an essential aspect for medical implants. A surface enhancement technique can provide an array of unique surface properties that improve its biocompatibility and functionality as an implant. Polyurethane-based implants that have found extensively acclaimed usage as an implant in biomedical applications, especially in the area of cardiovascular devices, still lack any mechanism to ward off bacterial or platelet adhesion. To bring out such a defense mechanism we are proposing a surface modification technique. Graphene oxide (GO) in very thin film form was wrapped onto the electrospun fibroporous polycarbonate urethane (PCU) membrane (GOPCU) by a simple method of electrospraying. In the present study, we have developed a simple single-step method for coating a polymeric substrate with a thin GO film and evaluated the novel antiadhesive activity of these films. SEM micrographs after coating showed the presence of very thin GO films over the PCU membrane. On the GOPCU surface, the contact angle was shifted by ∼30°, making the hydrophobic PCU surface slightly hydrophilic, while Raman spectral characterization and mapping showed the presence and distribution of GO over 75% of the membrane. A reduced platelet adhesion on the GOPCU surface was observed; meanwhile, bacterial adhesion also got reduced by 85% for Staphylococcus aureus (Gram positive, cocci) and 64% for Pseudomonas aeruginosa (Gram negative, bacilli). A cell adhesion study conducted using mammalian fibroblast cells projected its proliferation percentage in a MTT assay, with 82% cell survival on PCU and 86% on GOPCU after 24 h culture, while a study for an extended period of 72 h showed 87% of survival on PCU and 88% on GOPCU. This plethora of functionalities by a simple modification technique makes thin GO films a self-sufficient surface engineering material for future biomedical applications.
涉及聚合物生物材料的植入式设备的表面工程已成为医疗植入物的一个重要方面。表面增强技术可以提供一系列独特的表面性能，从而提高其生物相容性和作为植入物的功能。基于聚氨酯的植入物在生物医学应用中得到了广泛的应用，特别是在心血管设备领域，但仍然缺乏任何防止细菌或血小板黏附的机制。为了引入这种防御机制，我们提出了一种表面改性技术。通过简单的电喷雾方法，将非常薄的氧化石墨烯（GO）薄膜包裹在电纺纤维多孔聚碳酸酯聚氨酯（PCU）膜上（GOPCU）。在本研究中，我们开发了一种在聚合物基底上涂覆 GO 薄膜的简单单步方法，并评估了这些薄膜的新型抗黏附活性。涂层后的 SEM 显微照片显示，PCU 膜上存在非常薄的 GO 薄膜。在 GOPCU 表面，接触角发生了约 30°的偏移，使疏水的 PCU 表面略微亲水，而拉曼光谱特征化和映射显示，GO 存在于膜的 75%以上，并呈分布状态。在 GOPCU 表面上观察到血小板黏附减少，同时，金黄色葡萄球菌（革兰氏阳性，球菌）的细菌黏附减少了 85%，铜绿假单胞菌（革兰氏阴性，杆菌）的细菌黏附减少了 64%。使用哺乳动物成纤维细胞进行细胞黏附研究，在 MTT 测定中预测了其增殖百分比，PCU 上为 82%，GOPCU 上为 86%，在 24 h 培养后，PCU 上为 87%，GOPCU 上为 88%。通过简单的改性技术实现的多种功能使 GO 薄膜成为未来生物医学应用中自给自足的表面工程材料。
