Effect of polysaccharides from Polygonatum sibiricum on lipid-metabolism related mRNA and protein expression in hyperlipidemic mice / 中国中药杂志

To study the effect of polysaccharides from Polygonatum sibiricum on mRNA and protein expressions of blood lipid metabolism in hyperlipidemic mice. The mice were randomly divided into 6 groups, namely the blank control group, the hyperlipidemia model group, the simvastatin group, and low, middle and high-dose PSP groups (200, 400, 800 mg·kg⁻¹·d⁻¹). Each group of the mice was administrated intragastrically for 14 days, respectively. Subsequently, every group of mice, except for the blank control group, was intraperitoneally injected with 75% fresh egg yolk emulsion for establishing the hyperlipidemic mice model. Upon completion of the administration, the contents of TC, TG, LDL-C and HDL-C in serum of each group were investigated in details. In particular, the mRNA expression levels of PPAR-α, PPAR-, PPAR-, SREBP-1c, IL-6 and TNF-α of the liver tissues were detected by Real-time PCR, and the protein expression levels (including PPAR-α, PPAR-, PPAR-, SREBP-1c, IL-6, TNF-α) were examined by Western blot. Consequently, the obtained results showed that the contents of the serum TC, TG, LDL-C of low, middle and high-dose PSP groups significantly decreased compared with those of the hyperlipidemia model group. Simultaneously, there were significant differences between middle-dose and high-dose PSP groups (<0.01). In striking contrast, the contents of serum HDL-C of low, middle and high-dose PSP groups significantly increased, while obvious differences were also observed between middle-dose and high-dose PSP groups (<0.01). Moreover, middle-dose and high-dose PSR groups could up-regulate the protein and mRNA expressions of PPAR-α, PPAR- (<0.05) compared with those of the hyperlipidemia model group, and down-regulate the expressions of PPAR-,SREBP-1c, IL-6 and TNF-α(<0.05) compared with those of liver tissues of the hyperlipidemia model group. In conclusion, all of the above results suggested that PSP could inhibit the oxidation of the liver lipid, and regulate the expression levels of the corresponding genes and proteins relating to the lipid metabolism, so as to play a critical role for preventing hyperlipidemia.

Novel liposomal drug delivery system actively targeting Cryptococcus neoformans and elimination of infection / 药学学报

The purpose of this study is to develop a liposomal drug delivery system actively targeting Cryptococcus neoformans and explore its feasibility in therapy of cryptococcal infection. The specific fungibinding peptide was screened from 12-mer random phage display library, and linked to PEG-DSPE as the functional material of liposomes. The targeting capability of peptide-modified liposomes were investigated by fungi binding assay in vitro and fluorescence imaging in vivo. Itraconazole as a model drug were then encapsulated in the liposomes and were evaluated in pharmacodynamic test in vitro and for therapeutic effects against cryptococcal meningitis complicated with pulmonary cryptococcosis in vivo. The results showed that the peptide (sequence:NNHREPPDHRTS) could selectively recognize Cryptococcus and effectively mediate the corresponding liposomal formulation to accumulate in the infection site in vivo. This peptide-modified liposome has a small particle size (mean diameter of 88.25±2.43 nm) with a homogeneous distribution and high encapsulation efficiency (88.05±0.25%) of itraconazole. After intravenous administration, the pathogens were obviously eliminated in lung and brain, and the life-span of model mice were significantly prolonged, suggesting a promising potential of this cryptococcosis targeting strategy.

Construction of biotin-modified polymeric micelles for pancreatic cancer targeted photodynamic therapy / 药学学报

In this study, we explored the feasibility of biotin-mediated modified polymeric micelles for pancreatic cancer targeted photodynamic therapy. Poly (ethylene glycol)-distearoyl phosphatidyl ethanolamine (mPEG2000-DSPE) served as the drug-loaded material, biotin-poly(ethylene glycol)-distearoyl phosphatidyl ethanolamine (Biotin-PEG3400-DSPE) as the functional material and the polymeric micelles were prepared by a thin-film hydration method. The targeting capability of micelles was investigated by cell uptake assay in vitro and fluorescence imaging in vivo and the amounts of Biotin-PEG-DSPE were optimized accordingly. Hypocrellin B (HB), a novel photosensitizer was then encapsulated in biotinylated polymeric micelles and the anti-tumor efficacy was evaluated systemically in vitro and in vivo. The results showed that micelles with 5 mol % Biotin-PEG-DSPE demonstrated the best targeting capability than those with 20 mol % or 0.5 mol % of corresponding materials. This formulation has a small particle size [mean diameter of (36.74 ± 2.16) nm] with a homogeneous distribution and high encapsulation efficiency (80.06 ± 0.19) %. The following pharmacodynamics assays showed that the biotinylated micelles significantly enhanced the cytotoxicity of HB against tumor cells in vitro and inhibited tumor growth in vivo, suggesting a promising potential of this formulation for treatment of pancreatic cancer, especially those poorly permeable, or insensitive to radiotherapy and chemotherapy.

Long-circulating liposomal daptomycin enhances protection against systemic methicillin-resistant Staphylococcus aureus infection with improved therapeutic potential / 药学学报

In the face of escalating problems with pathogen control, the development of proper formulations of existing antibiotics is as important as the development of novel antibiotics. Daptomycin is a lipopeptide antibiotic with potent activity against Gram-positive bacteria. Currently, only injectable solution of daptomycin has been approved for clinical use. In the present study, the formulation of PEGylated liposomal daptomycin (PLD) was prepared and optimized, and its efficacy against methicillin-resistant Staphylococcus aureus (MRSA252) strains was investigated. The obtained PLD had a mean vesicle diameter of (111.5 +/- 15.4) nm and a mean percent drug loading of (5.81 +/- 0.19) % with high storage stability. Potent activity of PLD against MRSA was demonstrated in vitro with a more sustained effect than that of conventional liposomal daptomycin and daptomycin solution. In addition, intravenous administration of a single dose (equal to human use) of PLD significantly increased the survival of mice in a MRSA252 systemic infection model compared with other formulations. Drug distribution in the lung was significantly enhanced following administration of PLD, and no measurable tissue lesions or pathological changes were detected during PLD treatment. Taken together, PEGylated liposomes loaded with daptomycin may represent a promising approach to reduce MRSA252 infections, especially those involving bloodstream dissemination, such as hematogenous pulmonary infection.

Silica-coated ethosome as a novel oral delivery system for enhanced oral bioavailability of curcumin / 药学学报

The aim of this study is to investigate the feasibility of silica-coated ethosome as a novel oral delivery system for the poorly water-soluble curcumin (as a model drug). The silica-coated ethosomes loading curcumin (CU-SE) were prepared by alcohol injection method with homogenization, followed by the precipitation of silica by sol-gel process. The physical and chemical features of CU-SEs, and curcumin release were determined in vitro. The pharmacodynamics and bioavailability measurements were sequentially performed. The mean diameter of CU-SE was (478.5 +/- 80.3) nm and the polydispersity index was 0.285 +/- 0.042, while the mean value of apparent drug entrapment efficiency was 80.77%. In vitro assays demonstrated that CU-SEs were significantly stable with improved release properties when compared with curcumin-loaded ethosomes (CU-ETs) without silica-coatings. The bioavailability of CU-SEs and CU-ETs was 11.86- and 5.25-fold higher, respectively, than that of curcumin suspensions (CU-SUs) in in vivo assays. The silica coatings significantly promoted the stability of ethosomes and CU-SEs exhibited 2.26-fold increase in bioavailablity relative to CU-ETs, indicating that the silica-coated ethosomes might be a potential approach for oral delivery of poorly water-soluble drugs especially the active ingredients of traditional Chinese medicine with improved bioavailability.