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Purpose: The aim was to investigate anticancer drug-loaded poly(carbonate-ester) nanospheres as potential drug delivery systems for cancer therapy. Methods: Functional poly(carbonate-ester) copolymers (HPCP-SD) were synthesized by the incorporation of sulfadiazine as the tumor-targeting groups to hydroxyl groups of poly(carbonate-ester) copolymers. Two types of anticancer drug-loaded poly(carbonate-ester) nanospheres I and II were further prepared by dialysis method and high-voltage electrostatic field-assisted atomization, respectively, using HPCP-SD as polymeric carriers. These carriers and anticancer drug-loaded nanospheres were characterized, and their properties in vitro and in vivo were evaluated. Results: These anticancer drug-loaded poly(carbonate-ester) nanospheres had steady drug release rates and good controlled release properties. Moreover, anticancer drug-loaded poly(carbonate-ester) nanospheres II had faster drug release rates than those of anticancer drug-loaded nanospheres I. These anticancer drug-loaded nanospheres possessed lower cytotoxicity to HEK 293 cells and exhibited obviously higher anticancer efficiencies to the HeLa tumor cells than that of 5-fluorouracil. Anticancer drug-loaded nanospheres I possessed lower cytotoxicity to HEK 293 cells and higher anticancer activity to HeLa cells than those of anticancer drug-loaded nanospheres II. Conclusions: These anticancer drug-loaded poly(carbonate-ester) nanospheres showed the potential as drug delivery systems for cancer therapy. [ABSTRACT FROM AUTHOR]

Poly(9-phenyl-2,4,8,10-tetraoxaspiro-[5,5]undcane-3-one) (PPTC) was synthesized by the microwave-assisted ring-opening polymerization (MROP) of a six-membered cyclic carbonate monomer 9-phenyl-2,4,8,10-tetraoxaspiro-[5,5]undcane-3-one (PTC) with tin(II) 2-ethylhexanoate (Sn(Oct)) or aluminum isopropoxide (Al(OPr)) as the catalysts. The obtained polycarbonates were further reduced by apalladium/carbonate catalyst (10% Pd/C) to afford partly deprotected polycarbonates containing hydroxyl groups (HPPTC). These two types of polycarbonates were characterized by H-NMR, Fourier transform infrared spectroscopy (FTIR), UV, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and automatic contact-angle measurements. The influence of the feed molar ratio of monomer-to-catalyst, the microwave irradiation power and the reaction time on the polymerization was also studied. The experimental results showed that HPPTC possessed significantly higher hydrophilicity and water absorption rate than PPTC. [ABSTRACT FROM AUTHOR]

Folate-containing dextran ligand (FA-Dextran-DTPA) was synthesized by the incorporation of diethylenetriaminepentaacetic acid (DTPA) and folate (FA) as a tumor-targeting group into dextran as a polymer carrier. This ligand was further reacted with gadolinium chloride to make a dextran gadolinium complex FA-Dextran-DTPA-Gd. The ligand and its gadolinium complex were characterized by H-NMR, FTIR, UV-Vis, average particle sizes and zeta potential, as well. In vitro properties including relaxivity, cytotoxicity assay, cellular uptake assay, and magnetic resonance imaging (MRI) were also evaluated. Compared with Gd-DTPA, FA-Dextran-DTPA-Gd possessed obviously higher relaxation effectiveness and lower cytotoxicity to HeLa cells. FA-Dextran-DTPA-Gd had a high affinity to the H460 and MDA-MB-231 tumor cells and can be taken up selectively by these tumor cells. Moreover, FA-Dextran-DTPA-Gd showed enhanced signal intensities (SI) of MRI and enhanced the contrast of MR images of tumor cells. These results indicated that FA-Dextran-DTPA-Gd showed the potential as a tumor-targeting contrast agent in MRI. [ABSTRACT FROM AUTHOR]