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排序方式: 共有946条查询结果,搜索用时 15 毫秒
1.
目的:制备胡桃醌(juglone,Jug)聚乳酸-羟基乙酸(poly lactic-co-glycolic acid,PLGA)纳米粒(Jug-PLGA-NPs),并考察其理化性质、体外释放特征及对A375细胞的体外影响。方法:采用乳化挥发法制备Jug-PLGA-NPs,对其粒径、包封率、载药率以及体外释放特征进行考察;荧光显微镜观察PLGA-NPs在体外细胞的摄取情况,小动物活体成像仪观测PLGA-NPs在BALB/c荷瘤裸鼠尾静脉注射后体内的分布;用噻唑蓝(thiazolyl blue tetrazolium bromide,MTT)比色法检测其对A375细胞增殖抑制作用,流式细胞仪进行细胞凋亡率及细胞周期检测;蛋白免疫印迹法检测蛋白激酶B(protein kinase B,Akt),磷酸化-Akt(p-Akt),周期蛋白D1(cyclin D1)的表达情况。结果:制备的Jug-PLGA-NPs平均粒径为(149.6±21.5) nm,包封率为(68.39±2.51)%,载药率(5.07±0.98)%,具有良好的缓释特征。PLGA-NPs在体外细胞摄取和体内活体成像中具有良好的穿透和靶向性能。不同浓度Jug-PLGA-NPs均能明显抑制A375细胞增殖、促进细胞凋亡,呈明显时间浓度依赖性(P0.05),且48 h作用略优于等浓度Jug;其机制可能与调节Akt磷酸化水平,下调cyclin D1表达(P0.05),阻滞细胞于G0/G1期有关(P0.05)。结论:负载Jug的PLGA纳米微粒制备简便,具有良好的药物缓释、肿瘤靶向及抗肿瘤能力,为未来Jug的临床应用提供了一种新的药物剂型。  相似文献   
2.
目的优化丁香苦苷聚乳酸(Syr)-羟基乙酸共聚物[poly(lactic-co-glycolic acid),PLGA]纳米粒(Syr-NPs)的处方。方法采用纳米沉淀法制备Syr-NPs,以包封率、载药量、平均粒径以及总评"归一值"为评价指标,采用星点设计-效应面法考察PLGA质量浓度(A)、丁香苦苷质量浓度(B)、水相与有机相比例(C)3因素考察对包封率、载药量、平均粒径以及总评归一值的影响,以星点设计-效应面法选取最佳处方条件进行预测分析。结果最优处方工艺为PLGA质量浓度为9.63 mg/mL,Syr质量浓度为12.88 mg/mL,有机相与水相的比例为1∶9.46,制得的Syr-NPs的包封率、载药量、平均粒径分别为(27.86±0.87)%、(7.02±0.15)%、(110.0±1.20)nm。结论该方法稳定可行,可用于优化包载Syr的PLGA纳米粒处方与制备工艺。  相似文献   
3.
尹元元  耿燕娜  范明松 《中草药》2021,52(22):6806-6815
目的 Box-Behnken设计-效应面法(Box-Behnken design-response surface method,BBD-RSM)优化延胡索乙素(THP)聚乳酸-羟基乙酸共聚物[poly(lactic-co-glycolic acid),PLGA]纳米粒(THP-PLGA-NPs)处方,并进行体外评价。方法 纳米沉淀法制备THP-PLGA-NPs,以包封率、载药量、多分散系数(polydispersity index,PDI)和粒径大小为评价指标,单因素结合BBD-RSM筛选最优处方,采用甘露醇作为冻干保护剂制备成冻干粉,将最优处方进行表征及体外释放实验。结果 最佳处方为PLGA用量为491.8 mg、油水体积比1:5.2、乳化剂质量分数为1.12%。THP-PLGA-NPS包封率为(185.07±1.06)%,载药量为(4.73±0.21)%,粒径为(181.32±7.14)nm,分别与模型预测值接近。体外释药具有明显的缓释特征,释药过程符合Higuchi模型:Mt/M=0.112 4 t1/2+0.078 0,r=0.987 9。结论 Box-Behnken实验设计可用于THP-PLGA-NPS处方的筛选,且优化后的纳米粒具有缓释作用。  相似文献   
4.
5.
Poly(d,l-lactic-co-glycolic acid) (PLGA) nanoparticles (NP) of Val-Val dipeptide monoester prodrugs of ganciclovir (GCV) including L-Val-L-Val-GCV (LLGCV), L-Val-D-Val-GCV (LDGCV) and D-Val-L-Val-GCV (DLGCV) were formulated and dispersed in thermosensitive PLGA-PEG-PLGA polymer gel for the treatment of herpes simplex virus type 1 (HSV-1)-induced viral corneal keratitis. Nanoparticles containing prodrugs of GCV were prepared by a double-emulsion solvent evaporation technique using various PLGA polymers with different drug/polymer ratios. Nanoparticles were characterized with respect to particle size, entrapment efficiency, polydispersity, drug loading, surface morphology, zeta potential and crystallinity. Prodrugs-loaded NP were incorporated into in situ gelling system. These formulations were examined for in vitro release and cytotoxicity. The results of optimized entrapment efficiencies of LLGCV-, LDGCV- and DLGCV-loaded NP are of 38.7?±?2.0%, 41.8?±?1.9%, and 45.3?±?2.2%; drug loadings 3.87?±?0.20%, 2.79?±?0.13% and 3.02?±?0.15%; yield 85.2?±?3.0%, 86.9?±?4.6% and 76.9?±?2.1%; particle sizes 116.6?±?4.5, 143.0?±?3.8 and 134.1?±?5.2?nm; and zeta potential ?15.0?±?4.96, ?13.8?±?5.26 and ?13.9?±?5.14?mV, respectively. Cytotoxicity studies suggested that all the formulations are non-toxic. In vitro release of prodrugs from NP showed a biphasic release pattern with an initial burst phase followed by a sustained phase. Such burst effect was completely eliminated when NP were suspended in thermosensitive gels with near zero-order release kinetics. Prodrugs-loaded PLGA NP dispersed in thermosensitive gels can thus serve as a promising drug delivery system for the treatment of anterior eye diseases.  相似文献   
6.
7.
Oxaceprol is well-defined therapeutic agent as an atypical inhibitor of inflammation in osteoarthritis. In the present study, we aimed to develop and characterize oxaceprol-loaded poly-lactide-co-glycolide (PLGA) nanoparticles for intra-articular administration in osteoarthritis. PLGA nanoparticles were prepared by double-emulsion solvent evaporation method. Meanwhile, a straightforward and generally applicable high performance liquid chromatography method was developed, and validated for the first time for the quantification of oxaceprol. To examine the drug carrying capacity of nanoparticles, varying amount of oxaceprol was entrapped into a constant amount of polymer matrix. Moreover, the efficacy of drug amount on nanoparticle characteristics such as particle size, zeta potential, morphology, drug entrapment, and in vitro drug release was investigated. Nanoparticle sizes were between 229 and 509 nm for different amount of oxaceprol with spherical smooth morphology. Encapsulation efficiency ranged between 39.73 and 63.83% by decreasing oxaceprol amount. The results of Fourier transform infrared and DSC showed absence of interaction between oxaceprol and PLGA. The in vitro drug release from these nanoparticles showed a sustained release of oxaceprol over 30 days. According to cell culture studies, oxaceprol-loaded nanoparticles had no cytotoxicity with high biocompatibility. This study was the first step of developing an intra-articular system in the treatment of osteoarthritis for the controlled release of oxaceprol. Our findings showed that these nanoparticles can be beneficial for an effective treatment of osteoarthritis avoiding side effects associated with oral administration.  相似文献   
8.
The objective of this work is to produce doxorubicin-loaded galactose-conjugated poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles (NPs) to be specifically recognised by human hepatoma cellular carcinoma (Hep G2) cells and assess NPs cytotoxicity. Doxorubicin-unloaded and doxorubicin-loaded galactose-conjugated PLGA NPs were prepared using an emulsion method and characterised for morphology, size, drug release behaviour, Hep G2 recognition and cell cytotoxicity. The produced doxorubicin-loaded PLGA-galactose-conjugate nanoparticles (PLGA-GAL NPs) are spherical in shape with a size of 365?±?74?nm, a drug encapsulation efficiency of 69% and released in a biphasic pattern with higher release rates at pH 5. In vitro cell studies confirmed the specific interaction between the receptors of Hep G2 and the PLGA-GAL NPs. Cell cytotoxicity tests showed that unloaded NPs are non-toxic and that doxorubicin-loaded NPs caused a cellular viability decrease of around 80%, therefore representing a promising approach to improve liver-specific drug delivery.  相似文献   
9.
目的 :制备复合异烟肼(H)、利福平(R)、吡嗪酰胺(Z)的聚乳酸-羟基乙酸(HRZ/PLGA)缓释微球,观察其理化性质和体外缓释特性。方法:以PLGA(450mg)为载体,避光条件下称取H(40mg)、R(60mg)、Z(125mg),采用复乳-溶剂挥发法制备HRZ/PLGA缓释微球,应用扫描电镜观察微球的形态特征;应用高效液相色谱法(HPLC)测定其载药量、包封率;采用溶出法、HPLC于3h、6h、12h、1d、2d、3d、6d、9d、12d、15d、20d、25d、30d、40d、50d测定H、R、Z三种药物的浓度,观察其是否均大于10倍最低抑菌浓度(MIC),计算其日均释药率、累计释药率。结果:HRZ/PLGA微球在电镜下观察呈圆球形,平均粒径为10.3±4.7μm;H、R、Z三种药物的载药量分别为(18.02±0.36)%、(22.46±0.24)%、(21.68±0.37)%,包封率分别为(54.79±1.13)%、(72.35±0.39)%、(67.21±0.68)%;体外缓释试验显示微球缓释前12d左右,三种药物的累计缓释度均超过了50%,日均释药率分别为5.05%、4.89%、6.86%;第12天后三药的缓释基本趋于稳定,日均释药率分别为0.17%、0.26%、0.16%;三种药物缓释到50d时均大于10倍MIC。结论:HRZ/PLGA微球具有优良的载药及药物缓释效果,是一种理想的复合抗结核药物缓释系统。  相似文献   
10.
Insufficient neovascularization is associated with high levels of resorption and necrosis in autologous and engineered fat grafts. We tested the hypothesis that incorporating angiogenic growth factor into a scaffold–stem cell construct and implanting this construct around a vascular pedicle improves neovascularization and adipogenesis for engineering soft tissue flaps. Poly(lactic-co-glycolic-acid/polyethylene glycol (PLGA/PEG) microspheres containing vascular endothelial growth factor (VEGF) were impregnated into collagen-chitosan scaffolds seeded with human adipose-derived stem cells (hASCs). This setup was analyzed in vitro and then implanted into isolated chambers around a discrete vascular pedicle in nude rats. Engineered tissue samples within the chambers were harvested and analyzed for differences in vascularization and adipose tissue growth. In vitro testing showed that the collagen-chitosan scaffold provided a supportive environment for hASC integration and proliferation. PLGA/PEG microspheres with slow-release VEGF had no negative effect on cell survival in collagen-chitosan scaffolds. In vivo, the system resulted in a statistically significant increase in neovascularization that in turn led to a significant increase in adipose tissue persistence after 8 weeks versus control constructs. These data indicate that our model—hASCs integrated with a collagen-chitosan scaffold incorporated with VEGF-containing PLGA/PEG microspheres supported by a predominant vascular vessel inside a chamber—provides a promising, clinically translatable platform for engineering vascularized soft tissue flap. The engineered adipose tissue with a vascular pedicle could conceivably be transferred as a vascularized soft tissue pedicle flap or free flap to a recipient site for the repair of soft-tissue defects.  相似文献   
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