Comparative evaluation of polymeric and amphiphilic cyclodextrin nanoparticles for effective camptothecin delivery

Camptothecin (CPT) is a potent anticancer agent. The clinical application of CPT is restricted by poor water solubility and instability under physiological conditions. Solubilization and stabilization of CPT were realized through nanoparticulate systems of amphiphilic cyclodextrins, poly(lactide-co-glycolide) (PLGA) or poly-ε-caprolactone (PCL). Nanoparticles were prepared with nanoprecipitation technique, whereas cyclodextrin nanoparticles were prepared from preformed inclusion complexes of CPT with amphiphilic cyclodextrins. Polymeric nanoparticles, on the other hand, were loaded with CPT:HP-β-CD inclusion complex to solubilize and stabilize the drug. Mean particle sizes were under 275 nm, and polydispersity indices were lower than 0.2 for all formulations. Drug-loading values were significantly higher for amphiphilic cyclodextrin nanoparticles when compared with those for PLGA and PCL nanoparticles. Nanoparticle formulations showed a significant controlled release profile extended up to 12 days for amphiphilic cyclodextrin nanoparticles and 48 h for polymeric nanoparticles. Anticancer efficacy of the nanoparticles was evaluated in comparison with CPT solution in dimethyl sulfoxide (DMSO) on MCF-7 breast adenocarcinoma cells. Amphiphilic cyclodextrin nanoparticles showed higher anticancer efficacy than PLGA or PCL nanoparticles loaded with CPT and the CPT solution in DMSO. These results indicated that CPT-loaded amphiphilic cyclodextrin nanoparticles might provide a promising carrier system for the effective delivery of this anticancer drug having bioavailability problems.     

Preparation and physicochemical characterization of a novel paclitaxel-loaded amphiphilic aminocalixarene nanoparticle platform for anticancer chemotherapy

Objectives This paper describes the development and optimization of a nanoparticle delivery platform for the anticancer agent, paclitaxel, using a novel amphiphilic carrier, tetrahexyloxy‐tetra‐p‐aminocalix[4]arene (A4C₆). Methods Nanoparticles were successfully prepared at pH 4 by an emulsion evaporation method whereby an organic phase containing paclitaxel : A4C₆ (molar ratio 1 : 10) was dispersed by probe sonication into an aqueous phase containing 0.5% w/v polyvinyl alcohol as stabilizer. Key findings The drug‐loaded nanoparticles had a mean size of 78.7 ± 20.7 nm, surface potential of 38.3 ± 7.67 mV, and paclitaxel loading and encapsulation efficiencies of 69.1 ± 5.3 µg drug/mg carrier and 50.4 ± 3.2%, respectively. Transmission electron micrographs showed discrete particles with no evidence of agglomeration. In‐vitro dissolution into phosphate buffered saline supplemented with 4% bovine serum albumin showed 32.7 ± 3.9%, 82.6 ± 5.3% and 91.0 ± 6.0% of the encapsulated paclitaxel load was released at 5, 72 and 120 h, respectively. Conclusions This is the first report on the use of amino‐substituted amphiphilic calixarenes for the encapsulation of anticancer agents. The nanoparticles produced were significantly smaller than, but had comparable drug loads to the Abraxane nanoparticles, and have the potential to achieve targeted delivery of paclitaxel to tumour tissues.     

Liposome formulation of paclitaxel with enhanced solubility and stability

Despite its strong antitumor activity, paclitaxel (Taxol®) has limited clinical applications due to its low aqueous solubility and hypersensitivity caused by Cremophor® EL and ethanol which is the vehicle used in the current commercial product. In an attempt to develop a pharmaceutically acceptable formulation that could replace Taxol®, a paclitaxel incorporated liposome has been constructed to improve solubility and physicochemical stability. The effect of various components of the liposome, including cholesterol and lipid, on the solubility and entrapment efficiency (EE) of paclitaxel was systematically investigated. The results showed that 5% (v/v) of polyethylene glycol 400 in the hydration medium of liposome significantly increased the solubility (up to 3.39 mg/mL) as well as the EE and the paclitaxel content in the liposome formulation composed of 10% (w/v) of S₁₀₀PC with cholesterol (cholesterol-to-lipid molar ratio = 10:90). When sucrose (sugar-to-lipid molar ratio = 2.3) was added as a lyoprotectant during the freeze-drying of the liposome, physicochemical stability of liposome was significantly improved. Moreover, the cytotoxicity of the final liposome formulation against MDA-MB-231 human breast cancer cell line was not significantly different from that of Taxol®. The enhanced aqueous solubility as well as the physicochemical stability of paclitaxel in the liposome formulation developed in this study could be a safer and effective alternative to the Cremophor® EL and ethanol formulation.     

Therapeutic efficacy of folate receptor-targeted amphiphilic cyclodextrin nanoparticles as a novel vehicle for paclitaxel delivery in breast cancer

Purpose: The aim of this study is to test folate-conjugated cyclodextrin nanoparticles (FCD-1 and FCD-2) as a vehicle for reducing toxicity and increasing the antitumor efficacy of paclitaxel especially for metastatic breast cancer.

Methods: For the evaluation of PCX-loaded FCD nanoparticles, animal studies were realised in terms of survival rate, tumour size, weight change, metastazis and histopathological examination.

Results: FCD-1 displayed significant advantages such as efficient targeting of folate receptor positive breast cancer cells and having considerably lower toxicity compared to that of Cremophor^®. When loaded with paclitaxel, FCD-1 nanoparticles, which have smaller particle size, neutral zeta potential, high encapsulation efficiency and better loading capacity for controlled release, emerged as an effective formulation in terms of cytotoxicity and high cellular uptake. In an experimental breast cancer model, anticancer activity of these nanoparticles were compatible with that of paclitaxel in Cremophor^® however repeated administrations of FCD-1 nanoparticles were better tolerated by the animals. These nanoparticles were able to localise in tumour site. Both paclitaxel-loaded FCD-1 and FCD-2 significantly reduced tumour burden while FCD-1 significantly improved the survival.

Conclusions: Folate-conjugated amphiphilic cyclodextrin nanoparticles can be considered as promising Cremophor^®-free, low-toxicity and efficient active drug delivery systems for paclitaxel.     

Excipient effects on in vitro cytotoxicity of a novel paclitaxel self-emulsifying drug delivery system

Paclitaxel is a potent chemotherapeutic agent currently administered intravenously in polyoxyethylated castor oil (Cremophor EL) and dehydrated ethanol (1:1) for the treatment of solid tumors. The objective of this work was to develop a novel self-emulsifying drug delivery system (SEDDS) devoid of cremophor for the i.v./oral delivery of paclitaxel and to investigate the in vitro cytotoxicity of the combined excipients. The SEDDS formulations were characterized in terms of droplet size using a ternary phase diagram. The Caco-2 cell line was used to monitor the cytotoxicity of the excipients. Cell viability was determined colorimetrically at 570 nm utilizing the MTT assay. The distribution of the formulations on the phase diagram indicated the presence of macroemulsions ( approximately 1 microm), submicron emulsions (50-200 nm), and microemulsions (below 10 nm). An increase in the sodium deoxycholate excipient content led to an increase in physical stability but caused more chemical degradation of the drug and more cytotoxicity. The drug in the novel SEDDS was chemically stable for at least 1 year when kept as a two-part formulation. The drug loading was increased by approximately fivefold compared to the marketed i.v. formulation; the excipients presented a significantly reduced cytotoxicity and led to a stable microemulsion.     

紫杉醇聚氰基丙烯酸正丁酯纳米粒对人卵巢癌细胞的毒性

目的:评价制备紫杉醇聚氰基丙烯酸正丁酯纳米粒(PTX-PBCA-NPs)的原料的生物安全性以及PTX-PBCA-NPs的细胞毒性。方法:采用四噻唑蓝法(MTT法)和检测乳酸脱氢酶(LDH)活性的方法考察空白PBCA-NPs及其聚合的原料、PTX-PBCA-NPs对L-02人正常肝细胞、卵巢癌敏感株(A2780)和卵巢癌耐紫杉醇肿瘤细胞株(A2780/T)的细胞毒性。结果:制备的空白PBCA-NPs只有在大于608 ng·mL-1时,对于L-02细胞具有明显的毒性(P<0.05);在质量浓度304～608 ng·mL-1,空白PBCA-NPs对A2780和A2780/T细胞有明显毒性(P<0.05)。与同一浓度PTX溶液比较,PTX-PBCA-NPs对A2780和A2780/T细胞的毒性作用明显(P<0.05)。结论:空白PBCA-NPs有一定的生物安全性,PTX-PBCA-NPs在对卵巢癌肿瘤细胞有一定的杀伤能力。     

Development of nonsurfactant cyclodextrin nanoparticles loaded with anticancer drug paclitaxel

In the current formulation of clinical use paclitaxel (PCX) is associated with solubilizers that may produce severe side effects. In this study, PCX was complexed to an amphiphilic cyclodextrin (CD), 6-O-CAPRO-beta-CD, capable of forming nanoparticles spontaneously in order to mask its physicochemical properties via the formation of inclusion complexes of the drug with amphiphilic CD before the nanoparticle is formed. Complexes have been characterized with various techniques such as (1)H NMR, Fourier Transform Infrared (FTIR), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) confirming the formation of inclusion complex between PCX and 6-O-CAPRO-beta-CD. Nanospheres and nanocapsules were prepared directly from the preformed PCX/6-O-CAPRO-beta-CD inclusion complex by the nanoprecipitation technique, showing a size from 150 to 250 nm for nanospheres and from 500 to 500 nm for nanocapsules. Zeta potentials of the nanospheres and nanocapsules indicate stable colloidal dispersions within the range of -18 to -39 mV. A 12-month physical stability was demonstrated for blank nanoparticles. PCX encapsulation was high with three-fold increase in loading when nanoparticles are prepared directly from preformed inclusion complexes of the drug with 6-O-CAPRO-beta-CD. In vitro liberation profiles of PCX from CD nanoparticles show a prolonged release profile for this drug up to 12 h for nanospheres and 24 h for nanocapsules.     

Three-step tumor targeting of paclitaxel using biotinylated PLA-PEG nanoparticles and avidin-biotin technology: Formulation development and in vitro anticancer activity

Despite recent advances in cancer therapy, many malignant tumors still lack effective treatment and the prognosis is very poor. Paclitaxel is a potential anticancer drug, but its use is limited by the facts that paclitaxel is a P-gp substrate and its aqueous solubility is poor. In this study, three-step tumor targeting of paclitaxel using biotinylated PLA-PEG nanoparticles and avidin-biotin technology was evaluated in vitro as a way of enhancing delivery of paclitaxel. Paclitaxel was incorporated both in biotinylated (BP) and non-biotinylated (LP) PEG-PLA nanoparticles by the interfacial deposition method. Small (mean size approximately 110nm), spherical and slightly negatively charged (-10mV) BP and LP nanoparticles achieving over 90% paclitaxel incorporation were obtained. The successful biotinylation of nanoparticles was confirmed in a novel streptavidin assay. BP nanoparticles were targeted in vitro to brain tumor (glioma) cells (BT4C) by three-step avidin-biotin technology using transferrin as the targeting ligand. The three-step targeting procedure increased the anti-tumoral activity of paclitaxel when compared to the commercial paclitaxel formulation Taxol((R)) and non-targeted BP and LP nanoparticles. These results indicate that the efficacy of paclitaxel against tumor cells can be increased by this three-step targeting method.     

Cremophor-free intravenous microemulsions for paclitaxel I: formulation, cytotoxicity and hemolysis

Two cremophor-free microemulsions, lecithin:butanol:myvacet oil:water (LBMW) and capmul:myvacet oil:water (CMW) for paclitaxel (PAC) were developed for intravenous (i.v.) administration. Six surfactants and four oils were screened with various combinations for maximal water incorporation and PAC solubility. Microemulsion regions were subsequently determined in ternary phase diagrams. Cytotoxicity in an MDA-M231 human breast cancer cell line and hemolytic potential were assessed in these systems compared to Taxol (cremophor EL:ethanol, 1:1, 6 mgPAC/ml). The maximal water incorporation into the lecithin:butanol surfactant blend was greater than that incorporated into capmul when combined with the oils screened. PAC solubility in myvacet oil was increased 1389-fold over its aqueous solubility. LBMW had a larger microemulsion region (46.5% of total ternary phase diagram) than that seen with CMW (18.6%). The droplet size of the dispersed phase was 111.5 (4.18)nm for LBMW and 110.3 (8.09)nm for CMW. Cytotoxicity of PAC was in decreasing order of: Taxol>LBMW>CMW. The IC50 values for LBMW and CMW ranged from 4.5 to 5.7 and >10 microM, respectively, as compared to that of Taxol (1.3 to 1.8 microM). Eighty-three percent, 68%, and 63% of red blood cells remain unlysed at a formulation volume to blood ratio of 0.035 in LBMW, CMW and Taxol. Promising microemulsions, LBMW and CMW were developed that can incorporate approximately 12 mg/g of PAC, substantially higher than its aqueous solubility (10.8 microg/ml) and that in the Taxol vehicle (6 mg/ml). PAC retained its cytotoxicity in the LBMW and CMW and was less likely to cause hemolysis compared to Taxol. This higher drug loading results in a smaller vehicle volume in required doses of these formulations and potentially less vehicle-related side effects are anticipated.     

Antitumoral activity of camptothecin-loaded nanoparticles in 9L rat glioma model

Camptothecin (CPT), a plant alkaloid, is a potent anticancer drug in cell culture studies but it is clinically inactive due to rapid hydrolysis under physiological conditions. The drug exists in two forms depending on the pH value, an active lactone form at pH below 5 and an inactive carboxylate form at basic pH and this is a reversible reaction. In this study, nanoparticulate delivery systems were developed with either amphiphilic cyclodextrins, poly(lactide-co-glycolide) or poly-?-caprolactone in order to maintain the active lactone form and prevent the drug from hydrolysis. All nanoparticles were prepared with nanoprecipitation technique. Mean particle sizes were 130–280 nm and surface charges were negative. The encapsulation efficiency was significantly higher for amphiphilic cyclodextrin nanoparticles when compared to polymeric nanoparticles. Nanoparticle formulations based on cyclodextrins showed a controlled release profile extended up to 12 days. 6-O-Capro-β-cyclodextrin (1.44 μg/60 μL CPT) and concentrated 6-O-Capro-β-cyclodextrin (2.88 μg/60 μL CPT) nanoparticles significantly modified the growth or lethality of the 9L gliomas, since the median survival time was 26 days for the untreated group and between 27 and 33 days for amphiphilic cyclodextrin nanoparticle groups. These results indicate that, CPT-loaded amphiphilic cyclodextrin nanoparticles may provide a promising carrier system for the effective delivery of CPT in comparison to polymeric analogues.     

Self-Assembled Biodegradable Nanoparticles Developed by Direct Dialysis for the Delivery of Paclitaxel

Purpose The main objective of this study was to obtain self-assembled biodegradable nanoparticles by a direct dialysis method for the delivery of anticancer drug. The in vitro cellular particle uptake and cytotoxicity to C6 glioma cell line were investigated. Methods Self-assembled anticancer drugs—paclitaxel-loaded poly(d,l-lactic-co-glycolic acid) (PLGA) and poly(l-lactic acid) (PLA) nanoparticles—were achieved by direct dialysis. The physical and chemical properties of nanoparticles were characterized by various state-of-the-art techniques. The encapsulation efficiency and in vitro release profile were measured by high-performance liquid chromatography. Particle cellular uptake was studied using confocal microscopy, microplate reader, and flow cytometry. In addition, the cytotoxicity of this drug delivery system was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on C6 glioma cell line to predict the possible dose response of paclitaxel-loaded PLGA and PLA nanoparticles. Results PLGA and PLA nanoparticles with or without vitamin E tocopherol polyethylene glycol succinate (TPGS) as an additive were obtained, in which the sustained release of paclitaxel of more than 20 days was achieved. The coumarin6-loaded PLGA and PLA nanoparticles could penetrate the C6 glioma cell membrane and be internalized. The cytotoxicity of paclitaxel-loaded nanoparticles seemed to be higher than that of commercial Taxol? after 3 days incubation when paclitaxel concentrations were 10 and 20 μg/ml. Conclusions Direct dialysis could be employed to achieve paclitaxel-loaded PLGA and PLA nanoparticles, which could be internalized by C6 glioma cells and enhance the cytotoxicity of paclitaxel because of its penetration to the cytoplasm and sustained release property.     

Cytotoxic evaluation of injectable cyclodextrin nanoparticles

Nanoparticles were prepared using beta-CDC6, which is an amphiphilic beta-cyclodextrin derivative modified on the secondary face with 6C aliphatic esters. A nanoprecipitation technique was used to prepare the blank nanoparticles without any surfactant and nanoparticles containing Pluronic F68 as surfactant in a concentration range of 0.1 to 1%. Nanoparticle formulations were characterized by particle size distribution and zeta potential measurements. Entrapment efficiency and in-vitro release profiles were determined and the cytotoxicity of these injectable nanospheres was evaluated against mouse fibroblast L929 cell line and human polymorphonuclear cells by methlythiazolyltetrazolium assay. As far as particle size and zeta potential are concerned, there is a relationship between surfactant presence and nanoparticle characteristics. However, these effects are not significant. It was also found that surfactant presence has no effect on model drug nimodipine encapsulation but accelerates the in-vitro release of the drug. Cell culture studies on mouse fibroblasts and human polymorphonuclear cells revealed a concentration-dependent cytotoxicity more pronounced in fibroblast cells. This led to the conclusion that the use of surfactants in injectable nanoparticles prepared from amphiphilic beta-cyclodextrins may lead to altered in-vitro properties and impaired safety for the drug delivery system.     

Characterization of amphiphilic dendrimer modified PEG-PLA nanoparticles prepared by a double emulsion-solvent evaporation method

Drug delivery by nanocarriers requires characterizations of suitable particle size, high drug loading and safety. In this work, we prepared an amphiphilic dendrimer modified PEG-PLA mixed nanoparticles (NPs) by a double emulsion-solvent evaporation (DESE) method. The particle size and drug encapsulation efficacy (EE) were compared to evaluate and optimize the preparation parameters. The mixed NPs had average size ranging from (102±1) nm to (137±5) nm, and the zeta potential turned to positive with incorporation of the amphiphilic dendrimer. The NPs showed different EE of docetaxel (DTX) and paclitaxel (PTX) with higher affinity to more lipophilic PTX. The blank mixed NPs showed little cytotoxicity, and the DTX-loaded NPs could effectively facilitate the antiproliferation activity on PC-3 cells. The NPs could be used as an effective drug delivery system, and its anti-tumor effect is worthy of further study.     

紫杉醇新剂型的研究进展

紫杉醇是一种广谱、高效的抗肿瘤药物,但由于其水溶性差,临床上应用的注射剂加入聚氧乙烯蓖麻油以增加紫杉醇的水溶性,但聚氧乙烯蓖麻油在体内会产生严重的毒副作用.为了解决紫杉醇注射剂中聚氧乙烯蓖麻油的毒性问题,开发紫杉醇新剂型是近年来新药研发的热点之一.该文综述了近年来研发的一些紫杉醇新剂型,如乳剂、胶束、环糊精包合物、脂质体、微球、纳米粒和药物释放支架等,并对其可行性进行了分析.     

Selective Targeting of the Novel CK-10 Nanoparticles to the MDA-MB-231 Breast Cancer Cells

The main objective of this project was to formulate novel decorated amphiphilic PLGA nanoparticles aiming for the selective delivery of the novel peptide (CK-10) to the cancerous/tumor tissue. Novel modified microfluidic techniques were used to formulate the nanoparticles. This technique was modified by using of Nano Assemblr associated with salting out of the organic solvent using K₂HPO₄. This modification is associated with higher peptide loading efficiencies, smaller size and higher uniformity. Size, zeta potential & qualitative determination of the adsorbed targeting ligands were measured by dynamic light scattering and laser anemometry techniques using the zeta sizer. Quantitative estimation of the adsorbed targeting ligands was done by colorimetry and spectrophotometric techniques. Qualitative and quantitative uptakes of the various PLGA nanoparticles were examined by the fluorescence microscope and the flow cytometer while the cytotoxic effect of the nanoparticles was measured by the colorimetric MTT assay. PLGA/poloxamer.FA, PLGA/poloxamer.HA, and PLGA/poloxamer.Tf have breast cancer MDA. MB321 cellular uptakes 83.8, 75.43 & 69.37 % which are higher than those of the PLGA/B cyclodextrin.FA, PLGA/B cyclodextrin.HA and PLGA/B cyclodextrin.Tf 80.87, 74.47 & 64.67 %. Therefore, PLGA/poloxamer.FA and PLGA/poloxamer.HA show higher cytotoxicity than PLGA/ poloxamer.Tf with lower breast cancer MDA-MB-231 cell viabilities 30.74, 39.15 & 49.23 %, respectively. The design of novel decorated amphiphilic CK-10 loaded PLGA nanoparticles designed by the novel modified microfluidic technique succeeds in forming innovative anticancer formulations candidates for therapeutic use in aggressive breast cancers.     

紫杉醇纳米乳剂的体内外考察

目的考察紫杉醇纳米乳剂的形态、粒径分布及急性过敏反应,研究紫杉醇注射剂及自制紫杉醇纳米乳剂在大鼠体内的药代动力学。 方法用HPLC法测定大鼠体内紫杉醇含量。数据用3P87处理,得到各主要药代动力学参数。 结果纳米乳剂平均粒径为17.2 nm。纳米乳剂急性过敏反应为阴性,而市售紫杉醇注射液急性过敏反应为阳性。血浆中杂质及制剂中辅料不干扰紫杉醇的测定。大鼠iv自制紫杉醇纳米乳剂及紫杉醇注射液后的药-时曲线均符合二室模型。数据用3P87处理,得到各主要药代动力学参数。纳米乳剂及注射液的k₁₀分别为0.57,1.29·h^-1,k₁₂分别为1.44,1.27·h^-1,k₂₁分别为3.08,0.51·h^-1,AUC分别为34.98,21.85 mg·h·L^-1。结论紫杉醇纳米乳剂较紫杉醇注射液毒性降低,可在一定程度上延长药物在大鼠体内的循环时间。     

Lyophilized Paclitaxel Magnetoliposomes as a Potential Drug Delivery System for Breast Carcinoma via Parenteral Administration: <Emphasis Type="Italic">In Vitro</Emphasis> and <Emphasis Type="Italic">in Vivo</Emphasis> Studies

No HeadingPurpose. The study reports in vitro and biological evaluation of lyophilized negatively charged paclitaxel magnetic liposomes as a potential carrier for breast carcinoma via parenteral administration.Methods. Paclitaxel in magnetoliposomes were extracted by centrifugation and quantified by high-performance liquid chromatography (HPLC). Biological properties were studied using pharmacokinetics, in vivo distribution and cytotoxicity assays, as well as a mouse model of EMT-6 breast cancer.Methods. Pharmacokinetic studies showed that encapsulation of paclitaxel in magnetoliposomes produced marked difference over the drug in Cremophor EL/ethanol pharmacokinetics, with an increased t_1/2 19.37 h against 4.11 h. For in vivo distribution, paclitaxel concentration of lyophilized magnetoliposomes in the tumor was much higher than that of lyophilized conventional liposomes or Cremophor EL/ethanol, whereas in heart it was much lower than the latter two formulations via s.c. and i.v. administration. Lyophilized paclitaxel magnetic liposomes showed more potency on the therapy of breast cancer than other formulations via s.c. and i.p. administration.Conclusions. The current study demonstrates that paclitaxel magnetoliposomes can effectively be delivered to tumor and exert a significant anticancer activity with fewer side effects in the xenograft model.     

Inorganic nanoparticles for hydrophobic anticancer drug delivery

OBJECTIVE Many drug candidates identified from natural products are poorly water-soluble.The surfactants used to disperse the hydrophobic anticancer drugs in water may cause a serious of acute hypersensitivity reactions.Nanotechnology provides an alternative strategy for delivery of anticancer drugs.In the present study,different inorganic nanoparticles are utilized as hydrophobic anticancer drug carriers.METHODS Different inorganic superparamagnetic iron oxide,platinum and gold nanoparticles were synthesized.The hydrophobic anticancer drugs such as curcumin,gambogic acid and doxorubicin(DOX)base were loaded into the porous area or onto the surface of the nanoparticles.Cellular uptake and biocompatibility of nanoparticles were studied in human glioblastoma U-87 MG cells.The anticancer effect of drug loaded nanoparticles was compared with that of free drugs.Photothermal conversion of platinum and gold nanoparticles was studied by irradiation of nanoparticles with a near-infrared laser.RESULTS The synthesized nanoparticles are readily internalized by U-87 MG cells,and the internalized nanoparticles are mainly localized in endosomes/lysosomes in cells.The nanoparticle-based drug carrier provides the aqueous dispersions of the hydrophobic drugs.In endosomes/lysosomes mimicking buffers with a pH of 4.5-5.5,pH-dependent drug release was observed from drug loaded nanoparticles.The intracellular drug content and cytotoxicity are significantly higher for drug loaded nanoparticles than free drug.Photothermal treatment has a synergistic effect on drug′s anticancer activity.CONCLUSION These results suggested inorganic nanoparticles is a promising intracellular carrier for hydrophobic anticancer drugs.     

The extraction of diethylhexylphthalate (DEHP) from polyvinyl chloride components of intravenous infusion containers and administration sets by paclitaxel injection

Paclitaxel injection (Taxol^TM) contains cremophor and ethanol in equal proportions, two agents known to leach diethylhexylphthalate (DEHP) from polyvinyl chloride (PVC) infusion bags and administration sets. The manufacturers of paclitaxel therefore recommend the use of glass, polypropylene or polyolefin containers for storage. This recommendation poses a number of practical problems since the availability of these other types of containers is severely limited and as such staff may be unfamiliar in their handling. The aim of this study was to investigate the extent of DEHP extraction by paclitaxel injection contained in PVC infusion bags and administered by either PVC or non-PVC sets in a bid to verify the manufacturers' recommendations to avoid using PVC containers. The results indicated that during a 3 h infusion period, increasing amounts of DEHP were leached into the paclitaxel vehicle from both the PVC infusion bags and the standard PVC sets. The amounts of DEHP extracted depended on the concentration of the paclitaxel vehicle, the length of contact between the injection vehicle and the container and the type of administration set used. DEHP concentration was at its lowest when a non-PVC set was used to administer the infusate. The addition of 300 and 600 mg paclitaxel to the infusate, administered by non-PVC sets, led to no significant increase in DEHP extraction. Comparative total amounts of DEHP extracted for each dose were 10.0 and 30.3 mg for the paclitaxel vehicle infusion through non-PVC sets and 13 and 30.5 mg respectively for the formulated drug plus vehicle. These amounts of DEHP are substantially less than those delivered during a blood transfusion. Furthermore, the possibility of chronic exposure to DEHP from paclitaxel administered under these conditions is negligible in patients receiving the drug on four to six occasions. The study concludes that there is only minimal risk of DEHP exposure from paclitaxel infusion contained in PVC bags and administered through non-PVC administration sets.     

Polylactide-Based Paclitaxel-Loaded Nanoparticles Fabricated by Dispersion Polymerization: Characterization,Evaluation in Cancer Cell Lines,and Preliminary Biodistribution Studies

The macromonomer method was used to prepare cross-linked, paclitaxel-loaded polylactide (PLA)–polyethylene glycol (stealth) nanoparticles using free-radical dispersion polymerization. The method can facilitate the attachment of other molecules to the nanoparticle surface to make it multifunctional. Proton nuclear magnetic resonance and Fourier transform infrared spectra confirm the synthesis of PLA macromonomer and cross-linking agent. The formation of stealth nanoparticles was confirmed by scanning and transmission electron microscopy. The drug release isotherm of paclitaxel-loaded nanoparticles shows that the encapsulated drug is released over 7 days. In vitro cytotoxicity assay in selected breast and ovarian cancer cell lines reveal that the blank nanoparticle is biocompatible compared with medium-only treated controls. In addition, the paclitaxel-loaded nanoparticles exhibit similar cytotoxicity compared with paclitaxel in solution. Confocal microscopy reveals that the nanoparticles are internalized by MCF-7 breast cancer cells within 1 h. Preliminary biodistribution studies also show nanoparticle accumulation in tumor xenograft model. The nanoparticles are suitable for the controlled delivery of bioactive agents. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:2546–2555, 2014