Differential Adhesive and Bioactive Properties of the Polymeric Surface Coated with Graphene Oxide Thin Film

Abstract

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.

Exposure of Smaller and Oxidized Graphene on Polyurethane Surface Improves its Antimicrobial Performance

“…Flat coatings without sharp edges, identical to the coatings containing GNP-M5ox obtained here were also reported by others using GO [20]. Thampi et al also observed wrinkled topography when spraying GO onto electrospun polycarbonate urethane (PCU) membranes [74]. Overall, coatings with GNP:PU ratio of 1:0.5, and specially with GNP concentration of 0.5 mg/mL, seemed to present more uniform and thus more promising surfaces.…”

Reduced graphene oxide-loaded nanocomposite scaffolds for enhancing angiogenesis in tissue engineering applications

“…Also, the short half-lives of such proteins in physiological conditions have led to some scepticism about the feasibility of using them as a therapeutic agent. In the recent years, there is a growing interest in using graphene-based materials for tissue engineering and other biomedical applications [ 20 , 21 ]. Graphene and reduced graphene oxide (rGO) are good conductors of electricity and have thus been used for neural tissue engineering applications [ 20 , 22 , 23 ].…”

Why Polyurethanes Have Been Used in the Manufacture and Design of Cardiovascular Devices: A Systematic Review

“…Thampi et al and Cortella et al used surface functionalization with antithrombotic agents or immobilization of molecules, such as polyethylene oxide (PEO), heparin, albumin, and chitosan (CS), to improve the blood compatibility of biomedical devices [ 2 , 43 ]. Roth et al and Yu et al recommended the application of biologically active substances, such as anticoagulants [ 14 ], fibrinolytic enzymes or proteins [ 14 ], heparin [ 22 ], CS [ 22 ], and dextran sulfate (DS) [ 22 ], as surface modification substances [ 14 , 22 ] in order to enhance the compatibility of PUs with the blood components.…”