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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 enhance the anticancer activity of doxorubicin(DOX) by conjugating DOX and vitamin E succinate (VES) and loading the conjugate into hyaluronic acid-octadecylamine (HA-C₁₈) copolymer micelles.METHODS DOX and VES were conjugated by amide reaction.DOX-VES/HA-C₁₈micelles were prepared via a probe-type ultrasonication technique.The morphology of the micelles was determined using a transmission electron microscopy (TEM).Dynamic light scattering (DLS) technique was used to determine the particle size distribution, hydrodynamic diameters, and stability of the micelles.Ultracentrifugation was exploited for measuring the drug loading (DL) and encapsulation efficiency (EE), and the in vitro release was investigated using a dialysis tubing.The cellular uptake and cellular distribution of drug-loaded micelles in MCF-7 cells were observed by fluorescence microscope, and the fluorescence intensity of DOX was evaluated by flow cytometer.The cytotoxicity of free DOX and drug-loaded micelles was tested by MTT assay against MCF-7 cells.RESULTS DOX-VES/HA-C₁₈ showed a nearly spherical morphology and good stability in PBS (pH 7.4) and 10% FBS.The particle size and zeta potential were (184.6??9.42) nm and (-20.7??1.23) mV, respectively.The DL and EE were (15.8??2.85)% and (94.2??1.32)%, respectively.DOX-VES/HA-C₁₈had a good controlled drug release property.Furthermore,DOX-VES/HA-C₁₈with accumulation in nucleipresented higher anti-tumor activity than free DOX and DOX/HA-C₁₈. CONCLUSION DOX-VES conjugate has synergistic anti-tumor effect and good application prospects.     

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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 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.     

pH/还原敏感型多柔比星前药胶束的制备及体外性能评价

目的 本实验以聚乙二醇 (polyethylene glycol,PEG) 和多柔比星(doxorubicin, DOX)合成的刺激敏感型前药聚合物(PEG-DOX)包载美法仑(melphalan,MEL),制备MEL/PEG-DOX纳米胶束,考察其体外协同抗肿瘤作用。方法 通过希夫碱反应将PEG化的二硫代二丙酸二酰肼(TPH)与DOX结合,形成pH/还原敏感型PEG-DOX前药纳米载体,通过其自组装性能制备MEL/PEG-DOX载药胶束。用透射电镜观察其形态,粒径仪测定其粒径和电位,用超滤法测定载药量和包封率,用透析法评价胶束的药物释放,采用MTT法评价细胞毒性。结果 通过核磁共振氢谱验证了所制备的刺激响应型PEG-DOX前药聚合物;其PEG-DOX载体平均粒径为(188±2.4)nm,多分散系数(PDI)为(0.255±0.008);MEL/PEG-DOX载药胶束的平均粒径为(299.7±2.4)nm,多分散系数(PDI)为(0.301±0.03),Zeta电位为(-0.385±0.02) mV;DOX载药量为(14.85±0.24)%,包封率是(85.78±0.37)%,MEL载药量为(7.36±0.36)%,包封率为(38.79±0.42)%;体外药物释放实验结果表明,MEL/PEG-DOX胶束具有还原敏感和pH敏感性,且还原敏感性大于pH敏感性;细胞毒性实验分析,DOX和MEL在细胞内共同释放,实现了对肿瘤细胞的联合杀伤。结论 MEL/PEG-DOX可以在肿瘤微环境特异性释放,对肿瘤细胞具有协调治疗的作用,具有良好的应用前景。     

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??OBJECTIVE To synthesize the biomacromolecule of poly-malic acid (PMLA) for preparation of a novel 2,3-dimethylmaleic anhydride-decorated polyethyleneimine-poly(??-L-malic acid)-doxorubicin nanoconjugate for effective and specific drug delivery. METHODS The structures of PMLA and the nanoconjugate were confirmed by ¹H-NMR. Then the conjugation efficiency and drug release property were determined. The cellular uptake and cytotoxicity were assessed by using human hepatocellular carcinoma (HCC) cell line Huh7 as in vitro cell model. RESULTS PMLA and DOX/PMLA-PEI-DMA were successfully prepared. The nanoconjugate possessed pH-sensitive charge-conversion and pH-dependent drug release properties. DOX/PMLA-PEI-DMA enhanced the cellular uptake of DOX and in vitro cytotoxicity effectively. CONCLUSION Nanoconjugate DOX/PMLA-PEI-DMA can be used as a promising drug carrier for its targeted and intracellular delivery.     

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??OBJECTIVE To prepare calcitonin/puerarin-PLGA-dual-loaded nanoparticles modified by chitosan, and investigate theirin vitro release behavior.METHODS CS-CT/PR-NPs were prepared by the double emulsion solvent evaporation technique with PLGA as a carrier material; the formulation of CS-CT/PR-NPs was optimized by orthogonal design; the morphology of CS-CT/PR-NPs was observed by transmission electron microscope;the mean particle size,particle size distribution and Zeta potential were measured by laser particle size analyzer; the entrapment efficiency and drug loading were measured by ultracentrifugation; the in vitro release behavior was studied by dialysis. RESULTS CS-CT/PR-NPs were spherical in shape with the mean particle size of(190??2.65) nm, particle size distribution of (0.117??0.027) and Zeta potentialof(16.5??1.08) mV. The entrapment efficiency was (75.7??1.15)%, and the drug loading of CT was (3.47??0.31)%, while those of PR were (50.9??1.08)% and (4.68??0.19)%, respectively. The profiles of in vitro release had the features of sustained-release. CONCLUSION CS-CT/PR-NPs are prepared successfully and show a sustained-release characteristic with high entrapment efficiency, which may improve the oral bioavailability of CT and provide the experimental reference for preparing the dual-loaded nanoparticles.     

多西他赛聚合物胶束的制备、表征及其对前列腺癌细胞LNCap-C4-2B的抑制作用

目的制备多西他赛-聚乙二醇-聚己内酯嵌段共聚物(PEG-PCL-DTX,DTX-PMs)胶束,研究多西他赛-聚乙二醇-聚己内酯嵌段共聚物的载药量、包封率及体外释放,考察对前列腺癌细胞株LNCaP-C4-2B的抑制增长效应。方法采用透射电镜观察纳米胶束的形态,采用激光粒度仪、高效液相色谱法对胶束的粒径,电位,载药量,包封率、体外释放进行研究;采用MTT法检测多西他赛-聚乙二醇-聚己内酯嵌段共聚物对前列腺癌细胞LNCap-C4-2B的抑制作用,并与市售的多西他赛(多帕菲)进行比较。结果多西他赛-聚乙二醇-聚己内酯嵌段共聚物胶束的载药量和包封率分别为(8.72±0.24)%和(98.1±1.6)%,平均粒径为(25.19±2.36)nm,电位为(0.64±0.15)mV;体外释放具有一定缓释效应;MTT试验结果显示,多西他赛-聚乙二醇-聚己内酯嵌段共聚物能够很好地抑制LNCaP-C4-2B细胞的增长。结论多西他赛能够被多包载制备成胶束,其粒径小,稳定性好,可显著提高多西他赛在水相中的浓度,在体外具有良好的缓释效果和肿瘤细胞抑制作用。     

伊马替尼胶束的制备与体外克服肿瘤耐药性的研究

目的 伊马替尼(imatinib,IMN)包埋于托可索仑(tocofersolan,TPGS)胶束中,以提高其水溶性,并对其理化性质进行表征,及与人源耐药细胞株MCF-7/ADR的作用效果。通过TPGS胶束运输IMN进入细胞,可克服肿瘤细胞的多药耐药性,提高抗肿瘤效果,为进一步体内药效研究提供基础。方法 采用薄膜分散法制备IMN-TPGS胶束,对其粒径、电位、形态、载药量和包封率及体外释放行为进行表征,考察该胶束对MCF-7/ADR细胞的抗肿瘤效果。结果 IMN-TPGS胶束平均粒径为(22.69±2.39)nm,表面呈电中性,外观圆整,载药量为(1.55±0.06)%,包封率为(63.49±2.42)%;具有较高的耐稀释性,血清稳定性和冻干-复溶稳定性;在体外释放72 h后,累积释放度近100%,释放速率缓慢;IMN-TPGS胶束对MCF-7/ADR的IC₅₀为12.27 μmol·L^-1,细胞毒性大,细胞内药物含量高,可诱导近半数细胞凋亡。结论 IMN-TPGS胶束粒径均一,分散性良好,稳定性高,具有较强抗稀释性,有利于体液长循环,对耐药细胞株有明显的抗肿瘤效果,在一定程度上可以克服其多药耐药性。