Advances in the study of organelles targeting nanocarriers / 药学学报

Modern drug delivery system demands high therapeutic efficacy and low toxicity which depends on efficient intracellular transportation of therapeutics to specific organisms, cells, even targeted organelles such as cytosol, nucleus, mitochondria, lysosome and endoplasmic reticulum. Intracellular barriers which prevent drug molecules accessing to their targets mainly include cell membrane, lysosomal degradation and the endomembrane system. Nanocarriers can preserve the bioactivities of protein, enzyme and DNA, and also they are easy to be modified and functionalized. In this paper, we summarized the intracellular fate of nanocarriers, especially how to bypass intracellular barriers and then target cytosol, nucleus, mitochondria, lysosome and endoplasmic reticulum by pharmaceutical modifications.

Study on alpha-asarone reservoir-type patch / 中国中药杂志

<p><b>OBJECTIVE</b>To prepare the alpha-asarone reservoir patch and investigate its release and transdermal absorption characteristics in vitro. The efficient enhancers were chosen to improve the drug's permeation rate.</p><p><b>METHOD</b>The alpha-asarone reservoir patch was prepared using 1% hydroxypropyl methylcellulose (HPMC) of ethanol solution as medium and ethylene vinyl acetate (EVA) membrane to control the release of drug. The Franz diffusion cells were used and several permeation enhancers were evaluated. High performance liquid chromatorgraphy (HPLC) was used to determine alpha-asarone's content and permeation rate.</p><p><b>RESULT</b>The release mechanisms of alpha K-asarone patch in vitro coincided with zero-order kinetic. 30% ethanol cooperates with 1% Isopropyl Myristate (IPM) have the best effect on permeation of the patch. The permeation rate reaches (20.67 +/- 1.33) microg x cm(-2) h(-1).</p><p><b>CONCLUSION</b>Ethanol combined with IPM is good permeation enhancer, which facilitated the permeation of alpha K-asarone to fit the clinical requirements. However, the further studies of the skin's stimulation and bioavailability are needed.</p>

Preparation and quality evaluation of quercetin self-emulsifyied drug delivery systems / 中国中药杂志

<p><b>OBJECTIVE</b>To prepare the quercetin self-emulsified formulation and evaluate its quality.</p><p><b>METHOD</b>The quercetin self-emulsified formulation was optimized based on the quercetin solubility in different oils, and the self-microemulsified efficiency of various combinations of emulsifier and co-emulsifier evaluated using the pseudo-ternary phase diagram. The microemulsion of morphology, size and zeta potential were examined. The quercetin of solubility in self-emulsified system was tested and the formulation stability was investigated by accelerated experiment.</p><p><b>RESULT</b>The blank self-emulsified system was composed of ethyl oleate/Cremophor EUL/butanol with weight ratio of 10: 54: 36. After being dilutied with water, the morphology of microemulsion was homogeneous small spherical drops observed under the electro-microscopy. The particle size and the zeta potential were 16.3 +/- 4.6 nm and 2.1 +/- 0.8 mV, respectively. The solubility of quercetin in self-emulsifing system was (62.42 +/- 0.11) mg x mL(-1), increased 2 229 folds compared with that of in water. The quality of quercetin self-emulsified formulation was stable during the 3 months storage at 40 degrees C.</p><p><b>CONCLUSION</b>The solubility of quercetin is significantly increased in self-emulsified system and the formulation is stable and easy to prepare.</p>

Preparation and release behavior of chitosan scaffolds encapsulating proteins loaded in PLGA microspheres / 药学学报

<p><b>AIM</b>To prepare cells scaffolds with the characteristics of sustained release of proteins.</p><p><b>METHODS</b>Chitosan scaffolds was prepared by freeze-drying. Porosity and water content of scaffolds were determined. Bovine serum album (BSA) was selected as a model protein. Poly (lactic-co-glycolic acid) (PLGA) microspheres were prepared by double emulsion solvent evaporation and encapsulated into chitosan scaffolds. The morphology of PLGA microspheres and various scaffolds were observed using scanning electron microscope. Release behavior of BSA from various chitosan scaffolds was investigated.</p><p><b>RESULTS</b>The chitosan scaffold represents porous. At the -70 degrees C of quenching temperature, the porosity and water content of chitosan scaffolds were 78.6% +/- 1.5% and 85.1% +/- 6.2%, respectively. PLGA microspheres can be uniformly encapsulated into scaffolds without any morphology change. Significant sustained release of BSA from PLGA microspheres encapsulated into scaffolds was obtained. The cumulative release at 168 h was only 33.5%, while that of BSA from chitosan scaffolds at 24 h was above 90%. The release behavior can be controlled by adjusting the amount of chitosan in scaffolds and the type of PLGA.</p><p><b>CONCLUSION</b>The novel chitosan scaffolds encapsulating PLGA microspheres proved to be a promising cells scaffolds with controlling the release of growth factors in tissue engineering.</p>

Gene expression of tumor cells both in vitro and in vivo enhanced by integrin-targeting adenovirus vector / 药学学报

<p><b>AIM</b>To construct an efficient recombinant viral vector for gene therapy.</p><p><b>METHODS</b>First-generation adenovirus (Ad) vector was modified with the RGD peptide inserted into the fiber. Both in vitro and in vivo experiments of gene expression in different tumor cells with conventional and recombinant vectors were conducted. RT-PCR was used for detecting the expression of coxackievirus and adenovirus receptor and integrin at the surface of Meth-A cells.</p><p><b>RESULTS</b>Fiber-mutant adenovirus vector showed a notably enhanced gene expression in A2058, B16BL6, OV-HM, and Meth-A tumor cells compared with that of conventional ones. In vivo study carried out using Meth-A tumor-bearing mice also demonstrated that the intra-tumoral injection of recombinant adenovirus induced strong gene expression in these CAR-deficient tumor cells.</p><p><b>CONCLUSION</b>The recombinant vector can be a promising one for effective cancer gene therapy.</p>

Cellular uptake behavior of antisense oligodeoxynucleotides polymethacrylate submicroparticles / 药学学报

<p><b>AIM</b>To survey the uptake behavior and subcellular distribution of antisense oligodeoxynucleotide polymethacrylate submicroparticles (AS-ODN-SMP) and infer its mechanism in MGC cell lines.</p><p><b>METHODS</b>MGC cells were incubated at certain concentration of AS-ODN-SMP or AS-ODN for 8 h at 4 degrees C or 37 degrees C. Then the fluorescence oligodeoxynucleotide- labeled cells were counted by flow cytometer and the intracellular fluorescence intensity was determined after incubated with chloroquine for 2 h.</p><p><b>RESULTS</b>Cellular uptake of oligodeoxynucleotides was significantly increased following application of AS-ODN-SMP and total intracellular fluorescence intensity was enhanced by 683 folds with the vehicle concentration of 20 microg x mL(-1). AS-ODN-SMP entranced to cells profoundly with temperature-dependent manner. Rare cells took on fluorescence when incubated at 4 degrees C, while 37 degrees C they were significantly increased. But the intracellular fluorescence intensity appeared same level in present or absent of chloroquine.</p><p><b>CONCLUSION</b>With the help of polyacrylate submicroparticles, oligonucleotides efficiently entranced the cells via endocytosis and could successfully escape the degradation in lysosome.</p>

Preparation of cationic liposomes and its role in enhancing cellular uptake of antisense oligonucleotides / 药学学报

<p><b>AIM</b>To prepare the liposomes which protect antisense oligodeoxynucleotides (ASON) against nuclease degradation and delivery ASON into cytoplasmic efficiently.</p><p><b>METHODS</b>A cationic derivative of cholesterol, 3 beta-[N-(N',N'-dimethylaminoethan)-carbamoyl] cholesterol (DC-Chol) was synthesized and used to prepare cationic liposome. The characteristics of liposomes/ASON complexes including size, drug loaded efficiency and structure were investigated. Cellular uptake of fluorescence labled ASON (FAM-ASON) under different condition was determined by flow cytometric analysis. Denatured polyacryamide gel electrophoresis (DPGE) was used to analyze the role of liposomes in protecting ASON.</p><p><b>RESULTS</b>The mean values of preliposomes and liposomes/ASON complexes size were 185.7 and 228.2 nm, respectively. Cationic liposomes showed a high adsorption capacity for ASON. When the +/- charge ratio exceeded 2:1, more than 90% of the ASON was loaded into liposomes. Agarose gel electrophoresis showed three different existence of ASON in liposomes formulation: free, absorbed and encapsulated types. Concerning cellular uptake, DC-Chol liposomes indicated high efficient effect of increasing cellular uptake of ASON. Compared with free ASON, the total fluorescence intensity in cytoplasma was significantly enhanced. The level of increasing was largely depended on +/- charge ratio. The cellular uptake of FAM-ASON decreased in the presence of serum. The cellular total fluorescence intensity in 10% and 30% fetal bovine serum of cultured medium were only 22.3% and 15.5% as that of serum-free media, respectively. DPGE confirmed that free ASON was rapidly degraded by DNase I while ASON encapsulated into liposomes was efficiently protected.</p><p><b>CONCLUSION</b>The cationic DC-Chol liposomes are shown to be promising carriers to deliver ASON into cytoplasma.</p>

Study on polymethacrylate nanoparticles as delivery system of antisense oligodeoxynucleotides / 药学学报

<p><b>AIM</b>To investigate the possibility of polymethacrylate nanoparticles (NP) for antisense oligodeoxynucleotides delivery system.</p><p><b>METHODS</b>The nanoparticles were prepared by evaporating ethenol solution containing Eudragit RL100 or RS100, and then mixtured with oligonucleotides. The morphology and size were investigated by a transmission electron microscope and Mastersizer particle characterization systems, and the cytotoxicity was evaluated by Trypan Blue staining and hemolysis test. The flow cytometer was used to determine the uptake of fluorescence-labelled oligodeoxynucleotides.</p><p><b>RESULTS</b>The morphology of nanoparticles showed spherical and orderly, the average diameter was about 127 nm, and almost the antisense oligodeoxynucleotides (ODN) were loaded when NP: ODN was 6.6. The uptake of ODN was significantly increased when loaded by nanoparticles, which well depended on the nanoparticles concentration. Meanwhile, slightly cytotoxicity was observed when high dose of nanoparticles was used.</p><p><b>CONCLUSION</b>The polymethacrylate nanoparticles appeared to be a promising vehicle for gene delivery.</p>

Study on the characteristics of antisense oligodeoxy-neucleotides-liposomes complex and cellular uptake / 药学学报

<p><b>AIM</b>To investigate factors affecting the properties of antisense oligodeoxy nucleotides (ASON)-liposomes complex and their cellular uptake.</p><p><b>METHODS</b>Three types of blank liposomes were prepared by reverse-phase evaporation vesicles, and the complex were obtained through physical absorption. The light microscope was used to observe morphology characteristics of the complex. Drug loading capacity was analyzed by agarose gel electrophoresis. The transfected cell percentage and means fluorescence intensity were determined by flow cytometric analysis using M3 myeloma cell as a model.</p><p><b>RESULTS</b>The neutral liposome showed no aggregation while the cationic liposomes appeared some different extent aggregation in different medium when associated antisense oligodeoxynucleotides. The drug loading capacity depended on the ratio of +/- and the cationic charge density on the lipid membrane. The two kinds of cationic liposomes appeared different principles of loading ASON. As far as cellular uptake, The neutral liposomes showed no improvement of cellular uptake of ASON. However, the cationic liposomes were shown to enhance the cellular uptake of ASON if the appropriate +/- charge ratio was used. The optimal cellular uptake was achieved when +/- charge ratio was at 0.5:1 and 1:1 for SA-I liposome and SA-II liposomes, respectively.</p><p><b>CONCLUSION</b>The cationic liposomes improved the loading capacity and cell uptake of antisense oligodeoxynucleotides, which was determined by +/- charge ratio and charge density.</p>