Significant Transport of Doxorubicin into the Brain with Polysorbate 80-Coated Nanoparticles

Purpose. To investigate the possibility of delivering of anticancer drugs into the brain using colloidal carriers (nanoparticles). Methods. Rats obtained 5 mg/kg of doxorubicin by i v. injection in form of 4 preparations : 1. a simple solution in saline, 2. a simple solution in polysorbate 80 1% in saline, 3. bound to poly (butyl cyanoacrylate) nanoparticles, and 4. bound to poly(butyl cyanoacrylate) nanoparticles overcoated with 1% polysorbate 80 (Tween^® 80). After sacrifice of the animals after 10 min, 1, 2, 4, 6, and 8 hours, the doxorubicin concentrations in plasma, liver, spleen, lungs, kidneys, heart and brain were determined after extraction by HPLC. Results. No significant difference in the body distribution was observed between the two solution formulations. The two nanoparticle formulations very significantly decreased the heart concentrations. High brain concentrations of doxorubicin (>6 g/g) were achieved with the nanoparticles overcoated with polysorbate 80 between 2 and 4 hours. The brain concentrations observed with the other three preparations were always below the detection limit (< 0.1 |g/g). Conclusions. The present study demonstrates that the brain concentration of systemically administered doxorubicin can be enhanced over 60-fold by binding to biodegradable poly(butyl cyanoacrylate) nanoparticles, overcoated with the nonionic surfactant polysorbate 80. It is highly probable that coated particles reached the brain intact and released the drug after endocytosis by the brain blood vessel endothelial cells.     

Indirect Evidence that Drug Brain Targeting Using Polysorbate 80-Coated Polybutylcyanoacrylate Nanoparticles Is Related to Toxicity

Purpose. To investigate the mechanism underlying the entry of the analgesic peptide dalargin into brain using biodegradable polybutylcyanoacrylate (PBCA) nanoparticles (NP) overcoated with polysorbate 80. Methods. The investigations were carried out with PBCA NP and with non biodegradable polystyrene (PS) NP (200 nm diameter). Dalargin adsorption was assessed by HPLC. Its entry into the CNS in mice was evaluated using the tail-flick procedure. Locomotor activity measurements were performed to compare NP toxicities. BBB permeabilization by PBCA NP was studied in vitro using a coculture of bovine brain capillary endothelial cells and rat astrocytes. Results. Dalargin loading was 11.7 µg/mg on PBCA NP and 16.5µg/ mg on PS NP. Adding polysorbate 80 to NP led to a complete desorption. Nevertheless, dalargin associated with PBCA NP and polysorbate 80 induced a potent and prolonged analgesia, which could not be obtained using PS NP in place of PBCA NP. Locomotor activity dramatically decreased in mice dosed with PBCA NP, but not with PS NP. PBCA NP also caused occasional mortality. In vitro, PBCA NP (10 µg/ml) induced a permeabilization of the BBB model. Conclusions. A non specific permeabilization of the BBB, probably related to the toxicity of the carrier, may account for the CNS penetration of dalargin associated with PBCA NP and polysorbate 80.     

Long-Circulating PEGylated Polycyanoacrylate Nanoparticles as New Drug Carrier for Brain Delivery

Purpose. The aim of this study was to evaluate the ability of long-circulating PEGylated cyanoacrylate nanoparticles to diffuse into the brain tissue. Methods. Biodistribution profiles and brain concentrations of [¹⁴C]-radiolabeled PEG-PHDCA, polysorbate 80 or poloxamine 908-coated PHDCA nanoparticles, and uncoated PHDCA nanoparticles were determined by radioactivity counting after intravenous administration in mice and rats. In addition, the integrity of the blood-brain barrier (BBB) after nanoparticles administration was evaluated by in vivo quantification of the diffusion of [¹⁴C]-sucrose into the brain. The location of fluorescent nanoparticles in the brain was also investigated by epi-fluorescent microscopy. Results. Based on their long-circulating characteristics, PEGylated PHDCA nanoparticles penetrated into the brain to a larger extent than all the other tested formulations. Particles were localized in the ependymal cells of the choroid plexuses, in the epithelial cells of pia mater and ventricles, and to a lower extent in the capillary endothelial cells of BBB. These phenomena occurred without any modification of BBB permeability whereas polysorbate 80-coated nanoparticles owed, in part, their efficacy to BBB permeabilization induced by the surfactant. Poloxamine 908-coated nanoparticles failed to increase brain concentration probably because of their inability to interact with cells. Conclusions. This study proposes PEGylated poly (cyanoacrylate) nanoparticles as a new brain delivery system and highlights two requirements to design adequate delivery systems for such a purpose: a) long-circulating properties of the carrier, and b) appropriate surface characteristics to allow interactions with BBB endothelial cells.     

聚山梨酯80对药品微生物限度检查的影响

目的：分析不同来源、不同浓度的聚山梨酯80对试验菌生长的影响,为聚山梨酯80在药品微生物限度检查中的应用提供参考。方法：取不同生产厂家、不同批号的聚山梨酯80,分别加入pH 7.0无菌氯化钠-蛋白胨缓冲液中,制备成3%、4%、5%、10%、15%、20%浓度(v/v)的溶液,作为供试液。按照中国药典2015年版四部通则1105和1106,进行需氧菌、霉菌和酵母菌计数方法适用性试验。同时进行控制菌大肠埃希菌、金黄色葡萄球菌和铜绿假单胞菌检查的方法适用性试验。结果：不同来源、不同浓度的聚山梨酯80对需氧菌计数和控制菌检查试验结果的影响差别较大,对霉菌和酵母菌计数试验结果影响差别不大。结论：不同来源、不同浓度的聚山梨酯80对试验菌的生长影响不同。药品微生物限度检查中使用聚山梨酯80时,需注意聚山梨酯80的来源不同对试验结果造成的差异。     

聚山梨酯80脂肪酸组成测定的研究

目的建立了聚山梨酯80中7种脂肪酸组成的测定方法,为提高聚山梨酯80的质量控制标准提供方法及依据。方法采用甲酯化法。以聚乙二醇20000为固定液,采用火焰离子检测器(FID);进样口温度为250℃;检测器温度为250℃;柱温采用程序升温,初温为210℃保持25min,以2℃·min-1升温至240℃,保持20min;分流比为10∶1;进样量为1μL;柱流量恒定方式,载气为高纯氮气,柱流速为2mL·min-1。结果选定的色谱条件下,7种脂肪酸甲酯分离良好;精密度均小于2.0%(n=6);重现性均小于3.0%(n=6);平均回收率均在95.6%～107.5%范围内(n=3);检出限分别为十四烷酸甲酯0.9μg·mL-1,棕榈酸甲酯0.8μg·mL-1,棕榈油酸甲酯1.0μg·mL-1,硬脂酸甲酯0.9μg·mL-1,油酸甲酯1.0μg·mL-1,亚油酸甲酯1.0μg·mL-1,亚麻酸甲酯1.5μg·mL-1。结论该方法准确、可靠,可用于聚山梨酯80中脂肪酸组成的检测。     

HPLC-ELSD测定莪术油注射液中聚山梨酯80的含量

目的用HPLC-ELSD测定莪术油注射液中聚山梨酯80的含量。方法色谱柱：TSK-GEL G2000 SWXL柱（7.8mm×300 mm,5μm）,流动相：20 mmol·L-1乙酸铵-乙腈（90∶10）;流速为0.6 mL·min-1;ELSD条件：漂移管（气化室）温度103℃,氮气流速2.3 L·min-1。结果该测定方法线性范围为：2.259~28.235μg,线性关系良好（r=0.997 8）;加样回收率为102.5%（n=6,RSD=1.73%）;重复性试验的RSD为0.60%（n=6）。结论本方法快速、准确、稳定,可用于莪术油注射液中聚山梨酯80的质量控制。     

骨髓靶向柔红霉素毫微粒的研究

采用乳液聚合法制备了柔红霉素聚氰基丙烯酸正丁酯毫微粒（１）,并对其形态,粒径分布,载药性,动物体内经时变化过程及骨髓靶向性进行了研究。结果表明１平均微粒径为７０ｎｍ,分布范围３０－２２０ｎｍ,包封率为９７．０％,载药一达５５．７％;小鼠胸脉注射相同剂量１及柔红霉素后,前者股骨内峰浓度提高到１．６２倍,ＡＵＣ提高到４．８７倍,总靶向效率从５．１７％提高到２４．１９％,表明１具骨髓靶向性。     

Direct Evidence That Polysorbate-80-Coated Poly(Butylcyanoacrylate) Nanoparticles Deliver Drugs to the CNS via Specific Mechanisms Requiring Prior Binding of Drug to the Nanoparticles

Purpose. It has recently been suggested that the poly(butylcyanoacrylate) (PBCA) nanoparticle drug delivery system has a generalized toxic effect on the blood-brain barrier (BBB) (8) and that this effect forms the basis of an apparent enhanced drug delivery to the brain. The purpose of this study is to explore more fully the mechanism by which PBCA nanoparticles can deliver drugs to the brain. Methods. Both in vivo and in vitro methods have been applied to examine the possible toxic effects of PBCA nanoparticles and polysorbate-80 on cerebral endothelial cells. Human, bovine, and rat models have been used in this study. Results. In bovine primary cerebral endothelial cells, nontoxic levels of PBCA particles and polysorbate-80 did not increase paracellular transport of sucrose and inulin in the monolayers. Electron microscopic studies confirm cell viability. In vivo studies using the antinociceptive opioid peptide dalargin showed that both empty PBCA nanoparticles and polysorbate-80 did not allow dalargin to enter the brain in quantities sufficient to cause antinociception. Only dalargin preadsorbed to PBCA nanoparticles was able to induce an antinociceptive effect in the animals. Conclusion. At concentrations of PBCA nanoparticles and polysorbate-80 that achieve significant drug delivery to the brain, there is little in vivo or in vitro evidence to suggest that a generalized toxic effect on the BBB is the primary mechanism for drug delivery to the brain. The fact that dalargin has to be preadsorbed onto nanoparticles before it is effective in inducing antinociception suggests specific mechanisms of delivery to the CNS rather than a simple disruption of the BBB allowing a diffusional drug entry.     

跨血脑屏障的药物递送策略研究进展

中枢神经系统（CNS）疾病是由各种复杂的缺血性、出血性、炎症性、神经退行性和发育性疾病引起的,是一类具有普遍性且治疗效果不佳的疾病。治疗CNS疾病的一个主要障碍是血脑屏障,它是一种保护大脑的、动态的、适应性强、功能高度复杂的天然屏障,许多具有治疗活性的药物被发现,但是由于其无法跨越血脑屏障,最终很难转化为有效的临床成果。综述跨血脑屏障实现药物脑递送的策略：干扰血脑屏障的紧密连接或外排系统、提高候选分子的血脑屏障透过性和载体偶联药物的脑递送,旨在为CNS药物的开发提供参考。     

聚山梨酯80质量标准的分析比较

目的:通过评价现行各国药典中聚山梨酯80的质量标准及相关文献,为进一步提高聚山梨酯80标准提供参考。方法:对美国药典、欧洲药典、英国药典、日本药典和《中国药典》中聚山梨酯80的质量标准进行了分析讨论,并对几项主要指标,如过氧化值、脂肪酸组成、环氧乙烷与二氧六环等的测定方法和限度进行了分析比较。过氧化值,日本药局方没有要求,其余四国药典要求一样,不得过10.0;脂肪酸组成,《中国药典》和日本药局方没有要求,美国药典、欧洲药典和英国药典的检测方法和限度完全相同;环氧乙烷与二氧六环,《中国药典》的检测要求达到欧美标准。结果与结论:提出了提高聚山梨酯80质量的方法和建议,为生产高质量的聚山梨酯80以及制定注射用聚山梨酯80的质量标准提供参考。     

Reaction to the paper: Interaction of Polysorbate 80 with Erythropoietin: A Case Study in Protein–Surfactant Interactions

Micelle-associated epoetin is still a possible explanation for the upsurge of pure red blood cell aplasia associated with subcutaneous use of epoetin alpha in patients with chronic renal failure.     

聚山梨酯80对药典方法检查中药注射剂蛋白的影响

目的:探究不同浓度的聚山梨酯80对中药注射剂蛋白检查药典方法——磺基水杨酸比浊法检测限量的影响。方法:采用磺基水杨酸比浊法分别检查牛血清白蛋白(BSA)和刀豆蛋白A(Con A)溶液,及其含有0.5%、1.0%、1.5%、2.0%、4.0%、6.0%、8.0%、10%聚山梨酯80的溶液,得到其检测限量。结果:BSA和Con A的检测限量分别是40μg和50μg。随着聚山梨酯80的浓度增大到10%,BSA和Con A的检测限量逐渐增大至140μg和100μg。结论:含有聚山梨酯80的中药注射剂不宜采用药典方法检查其蛋白。     

改进中国药典方法测定苦木注射液中聚山梨酯80的含量

目的建立苦木注射液中聚山梨酯80含量测定的可行性方法。方法采用硫氰酸钴铵比色法,制备标准曲线溶液、供试品溶液,分别在623 nm下测定吸光度,用标准曲线法计算含量。结果聚山梨酯80在0.4~1.2 mg·mL^-1浓度范围内,吸光度与浓度呈良好线性关系(r=0.9998);各浓度水平下的平均回收率为92%~105%,RSD为0.9%。结论本方法专属性强,精密、准确,可用于苦木注射液中聚山梨酯80的含量测定。     

Transport Across the Primate Blood-Brain Barrier of a Genetically Engineered Chimeric Monoclonal Antibody to the Human Insulin Receptor

Purpose. Brain drug targeting may be achieved by conjugating drugs,that normally do not cross the blood-brain barrier (BBB), to brain drugdelivery vectors. The murine 83-14 MAb to the human insulin receptor(HIR) is a potential brain drug targeting vector that could be used inhumans, if this MAb was genetically engineered to form a chimericantibody, where most of the immunogenic murine sequences arereplaced by human antibody sequence. Methods. The present studies describe the production of the gene forthe chimeric HIRMAb, expression and characterization of the protein,radiolabeling of the chimeric HIRMAb with 111-indium and125-iodine, and quantitative autoradiography of living primate brain taken 2hours after intravenous administration of the [¹¹¹In]chimeric HIRMAb. Results. The chimeric HIRMAb had identical affinity to the targetantigen as the murine HIRMAb based on Western blotting andimmunoradiometric assay using partially purified HIR affinity purified fromserum free conditioned media produced by a CHO cell line secretingsoluble HIR. The [¹²⁵I]chimeric HIRMAb was avidly bound to isolatedhuman brain capillaries, and this binding was blocked by the murineHIRMAb. The [¹¹¹In]chimeric HIRMAb was administeredintravenously to an anesthetized Rhesus monkey, and the 2 hour brain scanshowed robust uptake of the chimeric antibody by the living primatebrain. Conclusions. A genetically engineered chimeric HIRMAb has beenproduced, and the chimeric antibody has identical reactivity to thehuman and primate BBB HIR as the original murine antibody. Thischimeric HIRMAb may be used in humans for drug targeting throughthe BBB of neurodiagnostic or neurotherapeutic drugs that normallydo not cross the BBB.     

The Inclusion of a Matrix Metalloproteinase-9 Responsive Sequence in Self-assembled Peptide-based Brain-Targeting Nanoparticles Improves the Efficiency of Nanoparticles Crossing the Blood-Brain Barrier at Elevated MMP-9 Levels

This study investigated whether the inclusion of a matrix metalloproteinase-9 (MMP-9) responsive sequence in self-assembled peptide-based brain-targeting nanoparticles (NPs) would enhance the blood-brain barrier (BBB) penetration when MMP-9 levels are elevated both in the brain and blood circulation. Brain-targeting peptides were conjugated at the N-terminus to MMP-9-responsive peptides, and these were conjugated at the N-terminus to lipid moiety (cholesteryl chloroformate or palmitic acid). Two constructs did not have MMP-9-responsive peptides. NPs were characterised for size, charge, critical micelle concentration, toxicity, blood compatibility, neural cell uptake, release profiles, and in vitro BBB permeability simulating normal or elevated MMP-9 levels. The inclusion of MMP-9-sensitive sequences did not improve the release of a model drug in the presence of active MMP-9 from NPs compared to distilled water. ¹⁹F NMR studies suggested the burial of MMP-9-sensitive sequences inside the NPs making them inaccessible to MMP-9. Only cholesterol-GGGCKAPETALC (responsive to MMP-9) NPs showed <5% haemolysis, <1 pg/mL release of IL-1β at 500 μg/mL from THP1 cells, with 70.75 ± 5.78% of NPs crossing the BBB at 24 h in presence of active MMP-9. In conclusion, brain-targeting NPs showed higher transport across the BBB model when MMP-9 levels were elevated and the brain-targeting ligand was responsive to MMP-9.     

In Vivo and in Vitro Assessment of Baseline Blood-Brain Barrier Parameters in the Presence of Novel Nanoparticles

Purpose. Nanoparticles have advantage as CNS drug delivery vehicles given they disguise drug permeation limiting characteristics. Conflicting toxicological data, however, is published with regard to blood-brain barrier integrity and gross mortality. Methods. To address this issue two novel nanoparticle types: emulsifying wax/Brij 78and Brij 72/Tween 80 nanoparticles were evaluated in vivo for effect on cerebral perfusion flow, barrier integrity, and permeability using the in situ brain perfusion technique. Additional evaluation was completed in vitro using bovine brain microvessel endothelial cells for effect on integrity, permeability, cationic transport interactions, and tight junction protein expression. Results. In the presence of either nanoparticle formulation, no overall significant differences were observed for cerebral perfusion flow in vivo. Furthermore, observed in vitro and in vivo data showed no statistical changes in barrier integrity, membrane permeability, or facilitated choline transport. Western blot analyses of occludin and claudin-1 confirmed no protein expression changes with incubation of either nanoparticle. Conclusions. The nanoparticle formulations appear to have no effect on primary BBB parameters in established in vitro and in vivo blood-brain barrier models.     

Development of Nanoparticles for Drug Delivery to Brain Tumor: The Effect of Surface Materials on Penetration Into Brain Tissue

Surface-modified poly(d,l-lactic-co-glycolic acid) PLGA nanoparticles (NPs) were fabricated via nanoprecipitation for obtaining therapeutic concentration of paclitaxel (PTX) in brain tumor. The cellular uptake and cytotoxicity of NPs were evaluated on C6 glioma cells in vitro, and BALB/c mice were used to study the brain penetration and biodistribution upon intravenous administration. Results showed that by finely tuning nanoprecipitation parameters, PLGA NPs coated with surfactants with a size around 150 nm could provide a sustained release of PTX for >2 weeks. Surface coatings could increase cellular uptake efficiency when compared with noncoated NPs, and d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) showed the most significant enhancement. The in vivo evaluation of TPGS-PLGA NPs showed amplified accumulation (>800% after 96 h) of PTX in the brain tissue when compared with bare NPs and Taxol^®. Therefore, PLGA-NPs with PLGA-TPGS coating demonstrate a promising approach to efficiently transport PTX across blood-brain barrier in a safer manner, with the advantages of easy formulation, lower production cost, and higher encapsulation efficiency.     

纳米给药系统的药动学及毒理学研究进展

纳米给药是药剂学领域研究颇多的1种新型药物递送体系,具有超微体积及特殊结构,在控释、缓释、靶向给药以及黏膜、局部给药中,可提高难溶性药物与多肽药物的生物利用度,降低不良反应,在基因工程等领域中也显示出独特的优势。笔者综述了近年来报道的纳米给药系统在药动学、毒理学方面的研究,并简要介绍了纳米给药系统在药剂学领域中的研究进展。     

Blood-Brain Barrier Transport of Reduced Folic Acid

Purpose. The brain is relatively resistant to folic acid deficiency, indicating specialized transport systems may exist for this vitamin localized within the brain capillary endothelial wall, which makes up the blood-brain barrier (BBB) in vivo. The present studies quantify the BBB transport of [³H]-methyltetrahydrofolic acid (MTFA) in vivo and in isolated human brain capillaries in vitro. Methods. BBB transport of [³H]-MTFA was compared to that of [¹⁴C]-sucrose, a plasma volume marker, following either intravenous injection or intracarotid perfusion in anesthetized rats. Competition by 10 M MTFA or 10 M folic acid was examined to determine whether folic acid is also transported by the MTFA uptake system. Results. The BBB permeability-surface area (PS) product of [³H]-MTFA, 1.1± 0.3 L/min/g, was 6-fold greater than that of [¹⁴C]-sucrose following intravenous injection. The BBB PS product determined by intracarotid arterial perfusion was not significantly different from the BBB PS product calculated following intravenous injection. A time- and temperature- dependent uptake of [³H]-MTFA in human brain capillaries was observed. The uptake of [³H]-MTFA by either rat brain in vivo or by human brain capillaries in vitro was equally inhibited by 10 M concentrations of either unlabeled MTFA or unlabeled folic acid. Conclusions. (1) A saturable transport system exists at the BBB for folic acid derivatives and since this transport is equally inhibited by either folic acid or MTFA, it is inferred that this transport system is the folic acid receptor, and not the reduced folic acid carrier. (2) The presence of a folate transport system at the BBB may offer an endogenous transport system for brain drug delivery of conjugates of folates and drugs that do not normally cross the BBB in vivo.