Antiangiogenic Effect of Docetaxel and Everolimus as Individual and Dual-Drug-Loaded Micellar Nanocarriers

Purpose

The in vitro inhibitory effect of Docetaxel (DTX) and Everolimus (EVR) alone and together in poly(ethylene glycol)-block-poly(D,L-lactic acid) (PEG-b-PLA) nanocarriers on angiogenic processes and acute toxicity in mice was evaluated.

Methods

PEG-b-PLA DTX and/or EVR nanocarriers were characterized for size, drug loading, stability, and drug release. Cell proliferation, tubule formation, and migration studies were performed in Human Umbilical Vein Endothelial Cells (HUVEC) and Maximum Tolerated Doses (MTD) studies were in mice.

Results

DTX and EVR loading was 1.93 and 2.00 mg/mL respectively with similar solubilities for dual-drug micelles. All micelles were below 30 nm with diffusion controlled drug release. The IC₅₀ for DTX, EVR micelles were, 6.80?±?0.67, 18.57?±?2.86 and 0.65?±?0.11 nM respectively with a synergistic inhibitory effect for dual-drug nanocarriers. Significant inhibition of tube formation occurred upon treatment with dual-drug nanocarriers as compared to individual micelles. EVR presence in dual-drug nanocarriers was able to significantly increase the inhibition of the migration of HUVEC by DTX. The MTDs for EVR, DTX and dual-drug micelles were 50, 30 and 20 mg/kg for each respectively.

Conclusions

DTX-EVR dual-drug nanocarriers have antiangiogenic effects in vitro mediated through cellular angiogenic process and possess clinically relevant MTD.     

TAT介导的几种纳米药物载体的研究概况

TAT是一种应用最早且现今最为常用的细胞穿膜肽,已经成功与多种纳米载体如脂质体、胶束、纳米粒等连结形成可内化进入细胞内的载药体系。文章主要对TAT介导的几种纳米载药体系的穿透机制、体内外抗肿瘤活性及靶向病变部位能力等方面的研究进行综述,同时对微环境pH敏感的TAT靶向药物载体的研究进展作了简单介绍。     

Ethosomes as Nanocarriers for the Development of Skin Delivery Formulations

Pharmaceutical Research - The use of nanotechnology has been extensively explored for developing efficient drug delivery systems towards topical and transdermal applications. Ethosomes...     

Systematic Delivery of Chloroquine and Promethazine Using pH-Sensitive Polymers

Two pH sensitive polymers (Eudragit® L30 D55 and L100) were used as coating materials, respectively, for promethazine hydrochloride and chloroquine phosphate granules formulated with sodium carboxylmethylcellulose and Carbopol 940, respectively, in the ratios 1:1, 1:2, 1:3, and 1:4 (drug:polymer). The granules were characterized. Release studies for the uncoated and coated granules were studied in simulated gastric fluid and simulated intestinal fluid. Result obtained showed that 1:1 and 1:2 ratios of both coated and uncoated granules of the two drugs had short release times and could be recommended for rapid action, whereas 1:4 ratio with low release time could be used for sustained effect. The two granules could be used at varying ratios to obtain desired release characteristics, such that therapeutic concentrations of the two drugs could be achieved.     

多西他赛自微乳化释药系统的研究

目的：研制多西他赛自微乳化释药系统（DTX—SMEDDS）。方法：通过溶解度试验、处方配伍和伪三相图的绘制,以自微乳化时间、色泽和粒径的大小为指标,筛选油相、表面活性剂、助表面活性剂的最佳搭配和处方配比,制备获得DTX-SMEDDS,并对DTX-SMEDDS的分散粒径、电位和体外溶出度等进行了测定。结果：DTX-SMEDDS自微乳化稀释后的粒径为96．9nm,自微乳化时间〈1min,其在水中2h累积溶出百分率为82．39％,是原料药（2．35％）的约35倍。结论：所制备的DTX—SMEDDS大大提高了多西他赛的溶解和溶出,为进一步研发多西他赛新制剂提供了理论和试验依据。     

Poly(ethylene glycol)-modified Nanocarriers for Tumor-targeted and Intracellular Delivery

The success of anti-cancer therapies largely depends on the ability of the therapeutics to reach their designated cellular and intracellular target sites, while minimizing accumulation and action at non-specific sites. Surface modification of nanoparticulate carriers with poly(ethylene glycol) (PEG)/poly(ethylene oxide) (PEO) has emerged as a strategy to enhance solubility of hydrophobic drugs, prolong circulation time, minimize non-specific uptake, and allow for specific tumor-targeting through the enhanced permeability and retention effect. Furthermore, PEG/PEO modification has emerged as a platform for incorporation of active targeting ligands, thereby providing the drug and gene carriers with specific tumor-targeting properties through a flexible tether. This review focuses on the recent developments surrounding such PEG/PEO-surface modification of polymeric nanocarriers to promote tumor-targeting capabilities, thereby enhancing efficacy of anti-cancer therapeutic strategies.     

CD44‐Targeted Docetaxel Conjugate for Cancer Cells and Cancer Stem‐Like Cells: A Novel Hyaluronic Acid‐Based Drug Delivery System

A CD44‐targeted macromolecular conjugate of docetaxel was prepared via a pH‐sensitive linkage to hyaluronic acid and was characterized using NMR, gel permeation chromatography, and differential scanning calorimetry. The conjugated species were further evaluated in terms of drug release, cytotoxicity, cellular uptake, cell cycle inhibition, and subacute toxicity in mice. Cellular microscopic studies revealed that CD44‐expressing cells including MCF‐7 cancer stem cells and MDA‐MB‐231 metastatic breast cancer cells had internalized the conjugates via a selective receptor‐mediated mechanism, leading to cell cycle arrest in the G2/M phase. Hyaluronic acid–docetaxel conjugates showed specific toxicity only in CD44‐expressing cells in vitro, along with a decreased risk of neutropenia and dose‐dependent mortality in vivo. Hyaluronic acid–drug conjugates represent a promising and efficient platform for solubilization of sparingly soluble molecules as well as active and selective targeted delivery to cancer cells and cancer stem cells.     

含原酸酯基团的pH敏感纳米载体在抗肿瘤药物递送中的应用进展

pH敏感型纳米药物载体在癌症治疗方面的研究正受到越来越多的关注,显示出诸多优势和良好的应用前景。已报道的pH敏感型纳米药物载体包括多种类型。本文针对含原酸酯基团的pH敏感纳米药物载体,综述了其近年来的研究进展,并介绍了该类药物载体在抗肿瘤药物递送中的应用。     

一种新型的HA载药系统药物释放度的测定

目的:设计一种新型的透明质酸(HA)靶向载药系统,为开发治疗卵巢癌的美法仑靶向制剂奠定基础。方法:用活化的聚乙二醇对HA进行修饰后作为载体,与抗肿瘤药美法仑键合形成前药,再自组装成纳米胶束给药系统,并用高效液相法(HPLC)测定药物在模拟人体环境条件下的释药情况。结果:pH值会显著影响药物的累计释放量,P0.05;取样量对给药体系的累计释放量没有显著性影响,P0.05。结论:pH影响透明质酸酶的活性,所以会对药物的释放度带来影响。而取样量的对释放度没有显著性影响。     

pH敏感型热休克笼形蛋白纳米载体的构建及其理化性质评价

目的 设计并制备具有靶向肿瘤且pH敏感的热休克蛋白（heat shock proteins,HSP）笼形蛋白纳米递药系统,并对其理化性质进行表征。方法 采用基因全合成与蛋白质重组表达技术纯化HSP为母版,通过表面官能团功能化制备得到修饰穿膜肽Tat、聚乙二醇包衣的热休克笼形蛋白纳米载体（PT-HSP）。通过透射电镜、纳米粒度与Zeta电位测定仪对其形态、粒径及Zeta电位进行表征,并建立HPLC测定其载药量与包封率。考察载紫杉醇（paclitaxel,PTX）的PT-HSP在生理pH条件（pH 7.4）与肿瘤pH条件（pH 6.5）下的体外释药行为。结果 形态学结果表明,PT-HSP是呈现典型双层结构的均一球体,平均粒径为（154.4±23.6） nm,Zeta电位为（-2.6±0.7） mV。HPLC测得载PTX的PT-HSP的包封率为（75.3±3.6）%,载药量为（7.0±0.2）%。体外释药试验结果表明PT-HSP在pH 7.4条件下的释放速率显著慢于pH 6.5条件下的释放速率（P<0.01）。结论 本研究制备得到的pH敏感的HSP笼形蛋白智能纳米递药系统具有载药量高、稳定性强及智能靶向等优点,有望成为一种安全、有效、智能的抗肿瘤药物载体。     

AS1411 Aptamer/Hyaluronic Acid-Bifunctionalized Microemulsion Co-Loading Shikonin and Docetaxel for Enhanced Antiglioma Therapy

In this study, we developed an AS1411 aptamer/hyaluronic acid-bifunctionalized microemulsion co-loading shikonin and docetaxel (AS1411/SKN&DTX-M). Such microemulsion was capable of penetrating the blood-brain barrier (BBB), targeting CD44/nucleolin-overexpressed glioma, and inhibiting the orthotopic glioma growth. AS1411/SKN&DTX-M showed a spherical morphology with a diameter around 30 nm and rapidly released drugs in the presence of hyaluronidase and mild acid. In the U87 cellular studies, AS1411/SKN&DTX-M elevated the cytotoxicity, enhanced the cellular uptake, and induced the cell apoptosis. In the artificial blood-brain barrier model, the transepithelial electrical resistance was decreased after the treatment with AS1411/SKN&DTX-M and thereby of increasing the apparent permeability coefficient. Furthermore, AS1411/SKN&DTX-M showed a strong inhibition against the formation of cancer stem cell–enriched U87 cell spheroids, in which the expression of CD133 was downregulated significantly. In the biodistribution studies, AS1411/SKN&DTX-M could selectively accumulate in the brains of orthotopic luciferase-transfected U87 glioma tumor–bearing nude mice. Importantly, AS1411/SKN&DTX-M exhibited the overwhelming inhibition of glioma growth of orthotopic luciferase-transfected U87 glioma models and reached the longest survival period among all the treatments. In summary, the codelivery of shikonin and docetaxel using bifunctionalization with hyaluronic acid and AS1411 aptamer offers a promising strategy for dual drug-based combinational antiglioma treatment.     

Design of Hollow Hyaluronic Acid Cylinders for Sustained Intravitreal Protein Delivery

A hollow cylinder intravitreal implant was developed to achieve sustained release of protein to the retina for the treatment of retinal diseases. Hollow cylinders were fabricated by molding and cross-linking hyaluronic acid, the major component of the vitreous humor. Hollow cylinders were filled with a concentrated protein solution, and the properties of the cylinder walls were tested. Cross-linked hyaluronic acid hydrogels with swelling degrees as low as 2.7 were achieved as a means to extend the release of protein. Hollow cylinders were capable of releasing an antigen-binding fragment for over 4 months at a maximum release rate of 4 μg per day. Protein release from hollow cylinders was modeled using COMSOL Multiphysics^® software, and diffusion coefficients between 1.0 × 10^?11 and 3.0 × 10^?11 cm²/s yielded therapeutically effective levels of protein. Cylinders with a 1 mm outer radius were capable of loading >1 mg of protein while releasing at least 2.5 μg a day for over 4.5 months. Although smaller cylinders facilitate intravitreal placement, decreasing the cylinder radius severely limited drug loading. Design of hollow cylinder intravitreal implants must balance high drug loading to reduce device size with control of the diffusion coefficient to sustain protein release.     

Formulation and In-Vitro Characterisation of Cross-Linked Amphiphilic Guar Gum Nanocarriers for Percutaneous Delivery of Arbutin

Nano-colloidal systems formulated from amphiphilically-modified polysaccharides (degree of modification 16.6%) are focus of prominent study due to their potential to augment active penetration across the skin. Here we report the synthesis of amphiphilically-modified guar gum (GBE-GG) prepared by grafting with glycidol butyl ether (GBE), which were subsequently formed into nanocarriers and loaded with α-arbutin (22.3% loading). The monodispersed and close-to-spherical nanocarriers (size range 239–297 nm) formed via cross-linking were adequately stable mainly at low temperature (4 °C) under physiological pH condition. α-arbutin was released from GBE-GG NPs in a more sustained manner and the release profiles can be accurately represented by the 1^st order kinetic model. In-vitro interactions on immortalised human keratinocytes (HaCaT) cells revealed an increase in biological membrane permeability as well as the absence of cellular toxicity at application pertinent concentrations. No substantial haemolytic activity appeared and flow cytometry analysis revealed effective cellular uptake, suggesting their potential as promising nanocarriers for percutaneous delivery that warrants further comprehensive research.     

Multifunctional Tumor-Targeted Polymer-Peptide-Drug Delivery System for Treatment of Primary and Metastatic Cancers

Purpose  

In order to improve drug delivery to drug-resistant ovarian tumors, we constructed a multifunctional polymer-peptide-drug conjugate (PPDC) system for effective treatment of primary and metastatic ovarian cancers.     

多西他赛自微乳注射液在大鼠体内药动学及组织分布

目的测定大鼠单剂量（12．55mg／kg）尾静脉注射多西他赛自微乳溶液和市售注射剂的血药浓度,比较2组的药动学行为;研究多西他赛自微乳溶液和市售注射剂在正常大鼠心,肝,脾,肺,肾中的分布情况。方法采用高效液相法测定sD大鼠给药后不同时问点的血药浓度以及组织分布情况。结果多西他赛自微乳溶液组和市售制剂组的主要药动学参数除表观分布容积VI／F外,t1/2β,CL、AUC0→∞、MRT0→∞均无显著性差异（P〉0．05）。结论自制微乳与市售制剂在大鼠体内具有相似的动力学特征,没有显著改善药物在大鼠体内的组织分布。     

Investigation of Temperature-Responsive Tocosomal Nanocarriers as the Efficient and Robust Drug Delivery System for Sunitinib Malate Anti-Cancer Drug: Effects of MW and Chain Length of PNIPAAm on LCST and Dissolution Rate

In this study, for the first time, the coated tocosome by blend of chitosan, CS, and poly(N-isopropylacrylamide), PNIPAAm, was developed as the efficient and robust drug delivery system with improved drug encapsulation efficiency, extended stability, proper particle size and industrial upscaling for Sunitinib malate anti-cancer drug. Tocosome was synthesized by using Mozafari method as a scalable and robust method and without the need for organic solvents. The effects of tocosome composition and drug concentration on the stability, particle size of tocosome, zeta potential, encapsulation efficacy and loading of drug into it were investigated by Taguchi method, and optimum composition was selected for combining with the polymeric blend. Homopolymer of PNIPAAm was synthesized by two different polymerization methods, including free radical and reversible addition–fragmentation chain transfer (RAFT). Effects of molecular weight (MW) and chain length of the polymers on lower critical solution temperature (LCST) were examined. The developed nanocarrier in this research, CS-Raft-PNIPAAm-tocosome, indicated LCST value beyond 37°C (about 45°C) and this is suitable for hyperthermia and spatio-temporal release of drug particles.     

Mitochondrial Delivery of Doxorubicin by Triphenylphosphonium-Functionalized Hyperbranched Nanocarriers Results in Rapid and Severe Cytotoxicity

Purpose

To develop a novel hyperbranched polymer-based nanocarrier for efficient drug delivery to cell mitochondria. Also to study for the first time the cytotoxic effect of doxorubicin via mitochondria-specific delivery system.

Methods

We introduced alkyltriphenylphosphonium groups (TPP) to a poly(ethylene imine) hyperbranched polymer (PEI). We harnessed the hydrophobic assembly of these alkylTPP functionalized PEI molecules into ~100 nm diameter nanoparticles (PEI-TPP) and further encapsulated the chemotherapy agent doxorubicin (DOX), to produce the mitotropic nanoparticles PEI-TPP-DOX.

Results

By administering PEI-TPP-DOX to human prostate carcinoma cells DU145, we found that: (i) PEI-TPP-DOX specifically localized at cell mitochondria as revealed by the inherent DOX fluorescence; (ii) in contrast to the slow apoptotic cell death incurred by DOX over the period of days at micromolar concentrations, PEI-TPP-DOX triggered rapid and severe cytotoxicity within few hours of incubation and at submicromolar incubation concentrations. This cytotoxicity was mainly found to be of a necrotic nature, not precluding autophagy related death pathways to a smaller extent.

Conclusions

We have elaborated a versatile mitotropic nanocarrier; furthermore, using this platform, we have developed a mitochondrial-doxorubicin formulation with exceptional cytocidal properties, even in nanomolar concentrations.

Epidermal Growth Factor Receptor-Targeted Gelatin-Based Engineered Nanocarriers for DNA Delivery and Transfection in Human Pancreatic Cancer Cells

Type B gelatin-based engineered nanocarrier systems (GENS) have been used over the last several years as a non-condensing systemic and oral DNA delivery system. In this study, we have modified the surface of GENS with epidermal growth factor receptor (EGFR)-targeting peptide for gene delivery and transfection in pancreatic cancer cell lines. GENS were prepared by the solvent displacement method and the EGFR-targeting peptide was grafted on the surface using a hetero-bifunctional poly(ethylene glycol) (PEG) spacer. Plasmid DNA, encoding for enhanced green fluorescent protein (GFP), was efficiently encapsulated and protected from degrading enzymes in the control and surface-modified GENS. Upon incubation with EGFR over-expressing Panc-1 human pancreatic adenocarcinoma cells, the peptide-modified nanoparticles were found to be internalized efficiently by receptor-mediated endocytosis. Both quantitative and qualitative transgene expression efficiencies were significantly enhanced when plasmid DNA was administered with EGFR-targeted GENS relative to the control-unmodified gelatin or PEG-modified gelatin nanoparticle systems. Based on these preliminary results, EGFR-targeted GENS show tremendous promise as a safe and effective gene delivery vector with the potential to treat pancreatic cancer.     

Low-Molecular-Weight Methylcellulose-Based Thermo-reversible Gel/Pluronic Micelle Combination System for Local and Sustained Docetaxel Delivery

Purpose  

To develop low-molecular-weight methylcellulose (LMw MC)-based gel/Pluronic F127 micelle combination system for local and sustained delivery of docetaxel (DTX).