No abstract

A green and facile method for preparing biopolymer functionalized reduced graphene oxide (RGO) by using mussel inspired dopamine (DA) as the reducing reagent and the functionalized molecule is proposed. In the study, GO is reduced by DA and DA is adhered to RGO by one-step pH-induced polymerization of DA (polydopamine, PDA), and then heparin or protein is grafted onto the PDA adhered RGO (pRGO) through catechol chemistry. The obtained pRGO, heparin grafted pRGO (Hep-g-pRGO), and BSA grafted pRGO (BSA-g-pRGO) exhibit fine 2D morphology and excellent stability in water and PBS solution. Furthermore, the biocompatibility of the biopolymer functionalized RGO are investigated using human blood cells and human umbilical vein endothelial cells (HUVECs). The biopolymer functionalized RGO exhibits an ultralow hemolysis ratio (lower than 1.8%), and the cellular toxicity assay suggests that the biopolymer functionalized RGO has good cytocompatibility for HUVEC cells, even at a high concentration of 100 mg mL À1 . Moreover, the high anticoagulant ability of Hep-g-pRGO indicates that the grafted biopolymer could maintain its biological activity after immobilization onto the surface of pRGO. Therefore, the proposed safe and green biomimetic method confers the biopolymer functionalized RGO with great potential for various biological and biomedical applications.

No abstract

No abstract

Research into the design of heparin and heparin-like/mimicking polymer-functionalized biomedical membranes is of tremendous interest to the biomedical sector in particular and is driven by potential diverse biomedical applications such as blood purification, artificial organs and other clinical medical devices. In this review, we highlight the progress of the recent research and propose potential biomedical applications in the fields of surface heparinization and the heparin-inspired modification of polymeric membranes. We summarize various surface heparinization strategies such as blending, surface coating, grafting, layer-by-layer assembly and mussel-inspired coating. Then, we classify the heparinlike/mimicking polymers and their applications in the design of heparin-mimicking biomedical membranes and draw some conclusions. The general concept of heparin-like/mimicking polymers is usually defined as heparan sulfates or synthetic sulfated/carboxylated polymers with comparable biologically mimicking functionalities as heparin, especially anticoagulant activity. Moreover, the potential biomedical applications and benefits of heparin and heparin-like/mimicking polymer-functionalized membranes in blood purification, artificial organs and tissue engineering are also discussed in each section. The heparin and heparin-like/mimicking polymer-functionalized membranes presented are Chong Cheng obtained his BS degree in 2010 from the Biomedical Engineering, College of Materials Science and Engineering, Sichuan University. Since June 2010, He became a Ph.D candidate in Biomedical Engineering, College of Polymer Science and Engineering, Sichuan University under the supervision of Prof. Changsheng Zhao. He is now doing visiting research work at University of Michigan under the supervision of Prof. Nicholas A. Kotov. His research interests include the blood and cell compatibility of polymeric hydrogels and composite biomaterials, biomedical lms/membranes for tissue engineering and regeneration medicine, self-assembly and biomimetic nanotechnology, and also the studies of biological functionalization and applications of nanomaterials, including nano/micro-gels, hybrid polymeric nanoparticles, carbon nanotubes and graphene. From 2010, his publication includes over 30 high quality papers in top material and chemical journals.