Preparation and evaluation of folate-modified lipid nanocapsules for quercetin delivery.

Folate-modified lipid nanocapsule encapsulated quercetin (QT-FALNC) was prepared with phase inversion method. The formulation was optimized by simplex lattice design with encapsulation efficiency and drug loading as index. The encapsulation efficiency and drug loading of the optimal formulation were 96.01% and 2.98%, respectively. The drug concentration in QT-FALNC suspension was 4.29 mg/mL. Under transmission electron microscopy, the QT-FALNC showed spherical shape with a narrow size distribution. The particle size and zeta potential of QT-FALNC were 36.2 nm and -4.76 mV, respectively. The pharmacokinetics study in rats showed that the mean retention time (MRT0-∞) of the non-targeting lipid nanocapsules (LNC) loading quercetin (QT-LNC) and the targeting QT-FALNC was 12.981 h and 15.086 h, respectively, indicating that LNC could prolong the effect of QT in vivo. The in vitro anti-proliferative activity and cellar uptake of QT-FALNC were studied on Hela and MCF-7/MDR cells. The results showed that both QT-LNC and QT-FALNC displayed a stronger cell-killing effect than free QT. The in vivo anti-tumor study indicated that both QT-LNC and QT-FALNC showed the significant inhibition effect on tumor growth in H22 tumor-bearing mice compared with the control. It can be concluded that lipid nanocapsule is a potential carrier for improving solubility and biological activity of QT.

Preparation and in vitro evaluation of apigenin loaded lipid nanocapsules.

In the present study, apigenin loaded lipid nanocapsules (AP-LNC) was prepared with phase inversion method and the formulation was optimized by simplex lattice design experiment with drug loading and encapsulation efficiency as the indexes. The drug loading and encapsulation efficiency of the optimal AP-LNC formulation were 1.26 +/- 0.05% and 95.86 +/- 0.38%, respectively. The drug concentration in the AP-LNC solution was 5.88 mg/mL. The shape of the AP-LNC was spherical with good dispersion. The average particle size and zeta potential of the AP-LNC were 46.1 nm and - 28.18 mV, respectively. The in vitro release experiments showed that the release behavior of AP from LNC fitted the two phase dynamics process. The anti-proliferative activity of the AP-LNC was investigated using the MTT assay, and the results showed AP-LNC could significantly enhance the inhibition rate to HepG2 cell and MCF-7 cell. It could be concluded that LNC was a potential carrier for improving solubility and biological activity of AP.

Advances in nanotechnology-based delivery systems for curcumin.

Curcumin (CUR), a bioactive component of turmeric, which is a commonly used spice and nutritional supplement, is isolated from the rhizomes of Curcuma longa Linn. (Zingiberaceae). In recent years, the potential pharmacological actions of CUR in inflammatory disorders, cardiovascular disease, cancer, Alzheimer's disease and neurological disorders have been shown. However, the clinical application of CUR is severely limited by its main drawbacks such as instability, low solubility, poor bioavailability and rapid metabolism. Multifarious nanotechnology-based delivery approaches have been used to enhance the oral bioavailability, biological activity or tissue-targeting ability of CUR. This article reviews potential novel drug delivery systems for CUR including liposomes, polymeric nanoparticles, solid lipid nanoparticles, micelles, nanogels, nanosuspensions, nanoemulsions, complexes and dendrimer/dimer, which provide promising results for CUR to improve its biological activities.

Advances in liver-directed gene therapy for hepatocellular carcinoma by non-viral delivery systems.

Hepatocellular carcinoma (HCC) is a malignancy with a high mortality. Gene therapy provides a promising way for the treatment of HCC. Efficient gene delivery system, suitable gene target and appropriate way of administration together determine the effect of gene therapy for HCC. In recent years, employing non-viral gene delivery systems in gene therapy for HCC has attracted a lot of attention. Compared with viral vectors, non-viral gene delivery systems are nearly non-immunogenic, relatively safer, less expensive to produce and can carry a good many of genetic materials. But the transfection efficiency of these vectors still needs to be improved. And the liver targeting is another problem that needs to be solved. Attaching ligands to the non-viral vectors to enhance the targeting ability to the specific receptor and targeting to molecular targets of HCC are the effective strategies. Adopting suitable ways of administration is also a factor that plays an important role to achieve liver targeting. This review introduced the advances in liver-targeted gene therapy by non-viral vectors including the efforts to overcome the low transfection efficiency and enhance the liver targeting effect.

Eudragit® S100 coated calcium pectinate microspheres of curcumin for colon targeting.

Currently, colon-specific drug delivery systems have been investigated for drugs that can exert their bioactivities in the colon. In this study, Eudragit® S100 coated calcium pectinate microsphere, a pH-dependent and enzyme-dependent system, as colon-specific delivery carrier for curcumin was investigated. Curcumin-loaded calcium pectinate microspheres were prepared by emulsification-linkage method, and the preparation technology was optimised by uniform experimental design. The morphology of microspheres was observed under scanning electron microscopy. Interactions between drug and polymers were investigated with differential scanning calorimetry (DSC) and X-ray diffraction. In vitro drug release studies were performed in simulated colonic fluid in the presence of Pectinex Ultra SP-L or 1% (w/v) rat caecal content, and the results indicated that the release of curcumin was significantly increased in the presence of 1% (w/v) rat caecal contents. It could be concluded that Eudragit® S100 coated calcium pectinate microsphere was a potential carrier for colon delivery of curcumin.

Lung-targeted delivery system of curcumin loaded gelatin microspheres.

The purpose of the study is to design and evaluate curcumin loaded gelatin microspheres (C-GMS) for effective drug delivery to the lung. C-GMS was prepared by the emulsification-linkage technique and the formulation was optimized by orthogonal design. The mean encapsulation efficiency and drug loading of the optimal C-GMS were 75.5 ± 3.82 % and 6.15 ± 0.44%, respectively. The C-GMS presented a spherical shape and smooth surface with a mean particle diameter of 18.9 µm. The in vitro drug release behavior of C-GMS followed the first-order kinetics. The tissue distribution showed that the drug concentrations at lung tissue for the C-GMS suspension were significantly higher than those for the curcumin solution, and the Ce for lung was 36.19. Histopathological studies proved C-GMS was efficient and safe to be used as a passive targeted drug delivery system to the lung. Hence, C-GMS has a great potential for the targeted delivery of curcumin to the lung.