Introduction Curcumin (CUR) is a general ingredient of traditional Chinese medicine, which has potential antitumor effects. However, its use clinically has been limited due to its low aqueous solubility and bioavailability. In order to improve the therapeutic effect of CUR on osteosarcoma (i.e., bone cancer), a multifunctional micelle was developed here by combining active bone accumulating ability with tumor CD44 targeting capacity.Methods The CUR loaded micelles were self-assembled by using alendronate-hyaluronic acid-octadecanoic acid (ALN-HA-C18) as an amphiphilic material. The obtained micelles were characterized for size and drug loading. In addition, the in vitro release behavior of CUR was investigated under PBS (pH 5.7) medium containing 1% Tween 80 at 37℃. Furthermore, an hydroxyapatite (the major inorganic component of bone) affinity experiment was studied. In vitro antitumor activity was evaluated. Finally, the anti-tumor efficiency was studied.Results The size and drug loading of the CUR loaded ALN-HA-C18 micelles were about 118 ± 3.6 nm and 6 ± 1.2%, respectively. CUR was released from the ALN-HA-C18 micelles in a sustained manner after 12 h. The hydroxyapatite affinity experiment indicated that CUR loaded ALN-HA-C18 micelles exhibited a high affinity to bone. CUR loaded ALN-HA-C18 micelles exhibited much higher cytotoxic activity against MG-63 cells compared to free CUR. Finally, CUR loaded ALN-HA-C18 micelles effectively delayed anti-tumor growth properties in osteosarcoma bearing mice as compared with free CUR.Conclusion The present study suggested that ALN-HA-C18 is a novel promising micelle for osteosarcoma targeting and delivery of the hydrophobic anticancer drug CUR.
Yan Fufeng,Zhang Yuanchang,Zhang Shuai,Zhao Jihong,Liu Shunli,He Linghao,Feng Xiaozhong,Zhang Hongzhong,Zhang Zhihong
We report on an efficient method for the production carboxy-modified graphene (carboxy-GR), and its application to a highly sensitive immunoassay for the livestock feed additive clenbuterol. Octadecanoic acid is shown to self-assemble on carboxy-GR via intermolecular interaction. Goat anti-mouse IgG was conjugated to 1-octadecanethiol-modified carboxy-GR and then deposited by self-assembly on a C18-modified gold surface. The resulting sensor surface was used to quantify clenbuterol by both surface plasmon resonance and electrochemical impedance spectroscopy. The assay works in the 0.01 ng∙mL −1 to 10 ng∙mL −1 concentration range and the lower detection limit is 6.57 pg∙mL −1 . It is concluded that this fairly simple method can be extended to immunoassays for other food additives.
Principle of sensor system and immunoassay. (i) Binding of ACG–IgG with the alkyl chain of 1-octadecanethiol through intermolecular force onto the gold substrate; (ii) absorbance of Ab CLB onto the surface of ACG-IgG; and (iii) detection of CLB using an immunoassay based on Ab CLB –ACG–IgG.