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??OBJECTIVE To investigate the effect of chlorinated N-trimethyl chitosan (TMC??Cl) nanoparticle with different modified degrees on the transfection efficiency of mouse marrow-derived dendritic cells (DC) to provide a theoretical basis for the study of DC biological immune vaccine with chitosan (CS) nanoparticle adjuvant.METHODS TMC??Cl/pEGFP-C1 nanoparticles with different modified degrees were prepared by ion-crosslinking method. Particle size and Zate potential were measured by laser particle size analyzer. Nanoparticle quality was evaluated by enzyme protection experiment. DC were cultured in vitro by a modified Insba method, and TMC??Cl nanoparticles with different degrees of modification were analyzed by in vitro transfection experiments to verify the cytotoxicity and transfection efficiency.RESULTS The nanoparticle size was (220??15) nm, Zeta potential was (29??5) mV, encapsulation efficiency was 99.8%, and the transfection efficiency of TMC??Cl nanoparticles on DC in vitro increased by 10% than that of CS nanoparticles.CONCLUSION TMC??Cl nanoparticles can effectively improve the transfection efficiency of pEGFP-C1 plasmid in DC.     

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??OBJECTIVE To prepare a novel methotrexate sustained-release microspheres system, and study its in vitro release properties. METHODS The CS-montmorillonite (CS-MMT) intercalative composites were prepared by using chitosan and montmorillonite. The novel drug sustained-release system was prepared with CS-MMT as the carrier material and methotrexate as the model drug. The microspheres were characterized by Fourier transform infrared spectrometer (FTIR), electric microscope, UV-spectrophotometer (UV), as well as Malvernlaser particle size analyzer. The influences of the amount of composite materials, dosage of emulsifiers, ratio of oil/water and dosage of crosslinking agent on the drug loading and entrapment rate of microspheres were investigated. And in vitro release experiment was used to study the drug release properties of the microspheres. RESULTS The shape and size of the microspheres were uniform. The drug loading, average particle size and Zeta potential were 31.6%, 557.4 nm and 20.8 mV respectively under the optimal conditions, ie, ratio of water/oil of 1??5, amount of glutaraldehyde(aqueous phase)of 6%, dosage of emulsifiers (oil phase) of 7%, CS-MMT/CS ratio of 1??4, and MTX/CS ratio of 1??3. Methotrexate sustained-release system was pH-sensitive and tended to show a larger release percentage in hydrochloric acid solution. CONCLUSION CS-MMT can be used as a slow-release excipient. CS-MMT microspheres are good controlled-release carrier for drugs, with pH sensitivity.     

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??OBJECTIVE To prepare aziditaxel-loaded mPEG-PLA polymeric micelles, investigate its pharmaceutical characteristics and study its anti-tumor effects in vitro. METHODS Aziditaxel-loaded polymeric micelles were prepared by thin-film dispersion method. The morphology of aziditaxel-loaded micelles was observed under transmission electron microscope. The particle size distribution and Zeta potential of aziditaxel-loaded micelles were determined by dynamic light scattering method using a Malvern Zetasizer Nano ZS90 analyzer. The technical reproducibility and reconstitution stability of aziditaxel-loaded micelles were also checked. The drug loading and encapsulation efficiency were measured by HPLC. Dialysis method was used to investigate the in vitro release of aziditaxel-loaded micelles, and the release manner was fitted using the mathematic models. The in vitro anti-tumor activities were evaluated by proliferation inhibition and cycle block experiment. RESULTS Aziditaxel-loaded polymeric micelles were prepared successfully. Aziditaxel-loaded polymeric micelles showed spherical shape with a mean particle size of 24.50 nm, polydispersity index of 0.117 and Zeta potential of -10.06 mV. The mean drug loading and entrapment efficiency were (16.00??0.15)% and (95.80??0.10)%, respectively. The preparation reproducibility was fine, and the reconstitution solution of lyophilized preparation of aziditaxel-loaded polymeric micelles maintained stable within 6 h. The release behavior of aziditaxel-loaded micelles conformed to the ambiexponent model. Drug-loaded micelles could obviously inhibit the proliferation of MCF-7 breast cancer cell lines in vitro, and induce significant G₂/M cycle arrest and apoptosis on MCF-7 cancer cells. CONCLUSION Aziditaxel-loaded mPEG-PLA polymeric micelles are successfully prepared. The preparation method is simple, and the pharmaceutical properties of the products conform to the requirements of the subsequent study. The prepared aziditaxel-loaded polymeric micelles exhibit good application prospect with favourable in vitro anti-tumor activities.     

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??OBJECTIVE To prepare pyridostigmine bromide-phospholipids complex nanoemulsion (PPNE) and carry out in vitro and in vivo evaluation. METHODS The pyridostigmine bromide-phospholipids and PPNE were prepared by solvent evaporation method and pseudo-ternary phase diagram method, respectively. The morphology, particle size, Zeta potential, in vitro release and oral bioavailability of PPNE were evaluated. RESULTS The PPNE was approximately circular. The particle size and Zeta potential were 26.16 nm and -3.88 mV, respectively. The in vitro release behavior of PPNE was similar to pyridostigmine bromide. The relative oral bioavailability of PPNE was 208.1% to pyridostigmine bromide. CONCLUSION PPNE was successfully prepared with a simple and repeatable method, which may be a fundamental formulation for further research of pyridostigmine bromide.     

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??OBJECTIVE To synthesize hyaluronic acid-octadecene (HOY) copolymers by terminal thiolation modification of hyaluronic acid (HA), prepare doxorubicin-loaded micelles and investigate its pharmaceutical characteristics. METHODS HOY copolymers were synthesized through Michael addition reaction. The doxorubicin-loaded copolymer micelles were prepared with ultrasonic method, then the particle size, Zeta potential, encapsulation efficiency, drug loading efficiency and in vitro release behavior were studied. RESULTS HOY copolymers were synthesized successfully. The particle size and Zeta potential of the drug-loaded micelles were (237.2??2.7) nm and (-22.37??0.38) mV, and the encapsulation efficiency and drug loading rate were (89.8??0.011)% and (5.4??0.007)%, respectively. Moreover, the accumulative release of doxorubicin in vitro was about 70% in 48 h, indicating that the drug was released slowly from the micelles. CONCLUSION This study develops a new micellar system based on terminal modified HA, and provides a reference for the study of HA nanocarrier.
     

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??OBJECTIVE To prepare heparan sulfate-vitamin E succinate (HDV) amphipathic copolymers and explore the pharmaceutical properties of doxorubicin (DOX)-loaded HDV copolymer micelles (DOX/HDV). METHODS HDV copolymers were prepared by amide reaction and its structure was confirmed by ¹H-NMR. DOX/HDV micelles were prepared by ultrasonic method. The particle size, morphology, Zeta potential, drug loading, entrapment efficiency, and in vitro drug release and cytotoxicity were evaluated. RESULTS HDV amphipathic copolymers were synthesized successfully. The particle size, PDI value and Zeta potential of drug-loaded micelles were (105.0??7.3) nm, (0.239??0.484) and (-21.4??2.6) mV, respectively. The encapsulation and drug loading rate were (76.22??0.76)% and (9.53?? 0.58)%, respectively. The results of drug release test in vitro showed that DOX was released slowly from the micelles. Cytotoxicity experiments indicated that blank micelles had no apparent toxicity against both tumor cells and normal cells. However, DOX/HDV micelles could inhibit the tumor cells growth obviously. CONCLUSION HDV copolymers can effectively load DOX with properties of drug sustained release and enhanced cytotoxicity against tumor cells in vitro, which indicates that HDV may be a potential candidate for cancer therapy.     

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??OBJECTIVE To prepare atorvastatin-loaded tetracycline-PEG-PLGA(TC-PEG-PLGA/ATO) polymeric micelles, and investigate its pharmaceutical characteristics and targeting function in vitro. METHODS The amphiphilic TC-PEG-PLGA conjugate was synthesized via an esterification reaction and identified by the ¹H-NMR. Water insoluble atorvastatin was loaded on TC-PEG-PLGA conjugate micelles via dialysis method. The morphology of TC-PEG-PLGA/ATO micelles was observed under transmission electron microscope. The particle size distribution and Zeta potential of TC-PEG-PLGA/ATO micelles were determined by dynamic light scattering method. The drug loading and encapsulation efficiency were measured by HPLC, and in vitro release behavior was investigated via dialysis method. In vitro cytotoxicity was assessed via MTT assay, and bone-targeting activity was investigated via binding to the hydroxyapatite powder. RESULTS TC-PEG-PLGA/ATO micelle was prepared successfully, and its particle size and Zeta potential were (47.2??4.7) nm and (-14.25??0.31) mV. The encapsulation efficiency and drug loading rate were(98.2??1.51)% and (8.71??0.23)%, respectively. Moreover, the accumulative release of ATO in vitro was about 70% in 48 h, which indicated that the drug was released slowly from the micelles. In vitro cell evaluation showed that TC-PEG-PLGA conjugate micelles were great biocompatibility with MC3T3-E1 cells within the concentration range of 100-500 ??g??mL^-1. In vitro targeting performance indicated that the proportion of the TC-PLGA NPs bound to Hap(87.94%) was greater than the bound proportion of PLGA NPs(18.59%). CONCLUSION The TC-PEG-PLGA/ATO micelles exhibit small partical size and good stability, and significantly increased ATO content in aqueous solution. TC-PEG-PLGA/ATO micelles have good delayed release behavior, safety and binding efficacy to the hydroxyapatite powder.