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A hyaluronic acid-chitosan-gadolinium (HA-CTS-Gd) nanosphere is prepared by HA modified CTS nanosphere and the complexation between Gd ions and functional groups in CTS and HA molecule. The nanosphere is used as a novel magnetic resonance imaging (MRI) contrast agent for targeting specific tumor. The results show that the HA-CTS-Gd nanosphere is stable in physiological environment due to the strong Gd chelating interaction between the abundant functional groups in HA and chitosan molecules, which leads to low toxicity. Moreover, the obtained nanosphere reveals a high CD44 targeting efficiency and relaxation efficiency in vitro, and it has a great agency for human colonic and mouse lymphatic tumor MRI in vivo. Thus, the novel MRI contrast agent can be taken up selectively by CD44 antigen and used as a potential MRI contrast agents in specific tumor.

A novel multi-modal lymph-targeted contrast agent, ZnO:Gd@hyaluronic acid (HA) nanospheres, is prepared by Gd dopped ZnO quantum dot, modified by silica shell and grafted by HA molecule. The physicochemical properties are characterized and the lymphatic targeting is evaluated in vitro. Moreover, the contrast agent is used for in vivo lymphoma magnetic resonance imaging (MRI). The results show that the ZnO:Gd@HA nanospheres with 19% of quantum yield and 5.8 mM-1 •s-1 of relaxivity could be used for in vivo lymphatic targeting studies. Furthermore, they are highly targeted to lymph system in vitro and in vivo, and highlight their MRI in lymph tumor. Thus, the novel MRI contrast agent can be taken up selectively by lymphatic system and used as a potential multi-modal contrast agent in lymphatic system.

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In this paper, the surface of ultra high molecular weight polyethylene (UHMWPE) scaffold is modified to improve the hydrophilicity and cell adhesion behavior with silk fibroin (SF) grafting. Fourier Transform Infrared Spectroscopy (FT-IR), scanning electron microscope (SEM), Thermogravimetric (TG) and water contact angle analysis are performed to characterize the chemical structure, hydrophilicity and the morphology of UHMWPE/SF composites. The results show that SF can coat on the surface of UHMWPE scaffold, and the chromic acid etching is more conducive to SF deposition. After chrome-acid etching, both of the hydrophilicity and SF deposition on the surface of UHMWPE scaffold are improved, and the coating amount of SF is 10.31%. Furthermore, there is no obvious decrease in mechanical properties, which proves that SF on the surface of UHMWPE scaffold has no effect on its mechanical properties. The cell adhesion experiments on UHMWPE scaffold are evaluated and the maximum cell viability appears in PECrSFs, which means that the biocompatibility is the best. All results have clearly indicated that the surface modification on UHMWPE scaffold with SF is an effective way of producing a suitably hydrophilic surface for their applications in biomedicine.