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Drug delivery mediated by hydrogel has shown great promise in controlled drug release field. We report here the development of a hydroxybutyl chitosan (HBC) thermo-sensitive gel to deliver doxorubicine hydrochloride (DOX·HCl) for cancer treatment. Concentrated HBC aqueous solution could transform into hydrogel within 30 s after injection under physiological temperature in non-chemical fashion. The properties of the HBC gels including chemical structure, surface morphology, and rheologic properties were studied. Gelation temperature and gelation time of HBC could be adjusted by HBC concentrations. The gel erosion rate in vivo was faster than solubilization rate in vitro. The mild inflammatory response caused by implantation of the hydrogel was acceptable. The DOX·HCl (1 mg/ml) loaded HBC gels displayed slow release rates that were independent of the HBC concentration, and significantly reduced viability of 4T-1 cells compared with the HBC gels after 1 day incubation. These results indicate that thermo-sensitive HBC hydrogels have promising potential as an injectable drug carrier for pharmaceutical applications. [ABSTRACT FROM AUTHOR]

In this study, a folate-modified-chitosan-coated liposome (FCCL) was prepared for tumor-targeted drug delivery. The folate-chitosan conjugates were characterized using H NMR and infrared spectrum analysis. The properties of folate-chitosan-coated liposomes (FCCLs) were studied and compared with those of traditional liposomes and chitosan-coated liposomes (CCLs). FCCLs were spherical in shape with a classic core-shell structure. Compared with conventional liposomes, FCCLs had larger size (average diameter: 182.0 nm), higher zeta potential (10.1 mV), prolonged drug release behaviors (55.76 % after 24 h), and better physical stability when stored at 25 °C, all similar to the properties of CCLs. With fluorescein as a model drug, fluorescein-loaded liposomes, CCLs, and FCCLs were prepared and their tumor targeting ability was evaluated according to the in vitro cellular uptake of fluorescein loaded nanoparticles by MCF-7 and HUVEC cells. Results demonstrated that FCCLs had a significant higher uptake by folate receptor positive cells (MCF-7) as compared to traditional liposomes and CCLs, which indicated that the FCCLs were promising nano-carriers for tumor-targeted drug delivery. [ABSTRACT FROM AUTHOR]