ABSTRACT
To target neovasculature and tumor cells, a novel cationic liposome with verteporfin (BPD) active-loaded in lumen (CLL) was designed and its basic in vitro and in vivo behaviors were evaluated in this study. Calcium acetate gradient loading method was applied to encapsulate BPD actively and cationic lipid (2,3-dioleoy-loxy-propyl)-trimethylammonium (DOTAP) was added by post-insertion for the positive charge of CLL. Results of characterization showed that the diameter and zeta-potential of CLL were around 100 nm and 28 mV, respectively. Compared with passive loading liposomes, CLL significantly enhanced the stability of BPD loading. What's more, the loaded BPD in lumen could switch off the fluorescence and photosensitization during blood circulation by homo-fluorescence resonance energy transfer (homo-FRET) effect, leading to the diminished phototoxicity to normal tissues. In vitro cellular uptake and cytotoxicity assay exhibited that positive charge dramatically enhanced the uptake of CLL both in vascular endothelial cells and tumor cells leading to superior therapeutic efficacy. In vivo study further showed that CLL reduced the clearance rate and increased tumor accumulation compared with passive loading group. Quantitative results of exvivo organ indicated that negligible CLL distributed in normal organs contributing to low phototoxicity. Animal experiments were conducted according to the Guidelines of the Experimental Animal Ethics Committee of Peking University Health Science Center and International Animal Experiments. In conclusion, we successfully designed a novel cationic targeting liposome that overcame the limitations of passive loading and significantly enhanced the efficacy of photodynamic therapy.
ABSTRACT
This study was designed to investigate the impacts of particle shape of micelles on cell uptake and tumor imaging applications. We designed and synthesized an ultra-pH sensitive PEG-iPDPA diblock polymer, and prepared it into wormlike micelles and spherical micelles by thin-film dispersion method and modified solvent evaporation method, respectively. Firstly, the pH responsiveness of two kinds of micelles was investigated in vitro. Both forms of micelles responded to pH sensitively, and each of them could reach 100 times of ON/OFF fold after conjugated with BDP fluorescent probe. Moreover, the cellular uptake of two forms of micelles depended on the concentration and incubation time. However, the amount of cellular uptake of spherical micelles was much higher than that of the wormlike micelles, which proved that the shape of nanoparticles had a great influence on the cellular uptake. The results of in vivo imaging revealed that the spherical micelles had a better tumor accumulation as well as tumor imaging outcomes. Finally, the biosafety of micelles was tested by MTT assay and H&E staining, which indicated that none of the two kinds of micelles had obvious toxicity. Collectively, these results suggest that the spherical micelles could be a better carrier compared with wormlike micelles in terms of cellular uptake, tumor accumulation and tumor detection.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the genetic diversity of main germplasm of Atractylodes macrocephala in China and the genetic differentiation of the germplasm of A. macrocephala.</p><p><b>METHOD</b>A molecular marker ISSR was used to analyze the genetic diversity of 7 populations of A. macrocephala and a population of A. lancea.</p><p><b>RESULT</b>Twelve primers were used in the PCR amplification of 86 samples of A. macrocephala and 5 samples of A. lancea. Sixty-three bands with sizes ranged from 100 to 2500 bp were generated from 12 primers. Of all the 63 bands, 55 bands were polymorphic among 86 individuals of A. macrocephala, the percentage of polymorphic bands were 87.30% at the species level. The percentage of polymorphic bands (PPL) for a single population ranged from 58.73% to 71.43% (mean, 64.85%). Among the 7 populations, a population from Panan, GM exhibited highest variability (PPL =71.43%; HE = 0.2835; I = 0.4267). A dendrogram constructed by an unweighted pair group method of cluster analysis showed that populations from Panan constructed one branch and separated from other populations. In the AMOVA analysis, low level of genetic differentiation among populations was detected, 90.52% of the variability existed in population.</p><p><b>CONCLUSION</b>The genetic diversity of cultivated A. macrocephala in China is high, which is good for the production of high quality herb medicine.</p>