Synthesis and characterization of folic acid-conjugated chitosan nanoparticles as a tumor-targeted drug carrier / 南方医科大学学报

<p><b>OBJECTIVE</b>To synthesize and characterize paclitaxel (PTX)-loaded folate-conjugated chitosan (FA-CTS/PTX) nanoparticles and evaluate its cytotoxicity in vitro.</p><p><b>METHODS</b>CTS/PTX and FA-CTS/PTX nanoparticles were prepared using reductive amidation and ionic gelation of chitosan with tripolyphosphate anions (TPP). The particle size was determined by laser scattering and the morphology observed using transmission electron microscopy, and the PTX content in the nanoparticles was determined using ultraviolet spectrophotometer at 227 nm. The in vitro cytotoxicity of the nanoparticles against HeLa cells was evaluated by MTT assay. Fluorescence microscopy was used to observe the HeLa cells incubated with FA-chitosan nanoparticles in the presence or absence of folic acid in the culture medium.</p><p><b>RESULTS</b>PTX loading did not cause adhesion of the FA-CTS nanoparticles, which presented with uniform spherical morphology with an average diameter of 282.8 nm. The loading and encapsulation efficiencies of FA-CTS/PTX were 9.0% and 75.4%, respectively. The FA-CTS nanoparticles showed a greater extent of intracellular uptake in the absence of folic acid, indicating that the cellular uptake of the nanoparticles occurred through endocytosis mediated by the folate receptors. The PTX-loaded FA-CTS nanoparticles exhibited potent cytotoxicity against HeLa cells, an effect 2- to 3-fold stronger than that of PTX-loaded CTS nanoparticles.</p><p><b>CONCLUSION</b>FA-CTS can be a promising drug carrier with high efficiency in condensing drug, good tumor-targeting ability and low cytotoxicity.</p>

The biological behavior of hepatocarcinoma stem cells in rats / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To study the biological behavior of hepatocarcinoma stem cells in rats.</p><p><b>METHODS</b>Primary liver carcinomas were induced in rats using diethylnitrosamine. Tumor cells from 8 rats were separated according to rats oval cell (OVC) markers CD34, c-Kit, Thy-1, AFP, CK7, CK8, CK14, CK18, CK19 and GGT and then they were separately injected into the livers of nude mice. The tumors grown from the different subpopulation of OVC markers in the nude mice livers (10 OVC markers negative or positive cells) were weighted 1 month after the inoculations. The hepatocarcinoma cell subpopulations with higher ability in causing tumor growths were further studied in vitro. The cell cycles and DNA content of those subpopulation cells were investigated using flow cytometry.</p><p><b>RESULTS</b>(1) Subpopulation cells with CK7(-), Thy-1(+) and AFP(+) markers had a higher ability in causing tumors in nude mice; (2) Subpopulation cells, exhibiting characters of TSC, had a low growth rate in vitro.</p><p><b>CONCLUSIONS</b>(1) Different subpopulations of hepatocarcinoma cells had different abilities in causing tumors in rats. Some subpopulation cells, such as CK7(-), Thy-1(+) and AFP(+) cells, have characteristics of tumor stem cells. (2) The hepatocarcinoma stem cells may have a low growth rate in vitro.</p>