BACKGROUND & AIMS: :The radiolabeling of the liposome surface can be a useful tool for in vivo tracking of therapeutic drug loaded liposomes. We investigated radiolabeling therapeutic drug (i.e. an antibiotic, amikacin) loaded liposomes with (99m)Tc, nebulization properties of (99m)Tc-labeled liposomal amikacin for inhalation ((99m)Tc-LAI), and its stability by size exclusion low-pressure liquid chromatography (LPLC). LAI was reacted with (99m)Tc using SnCl2 dissolved in ascorbic acid as a reducing agent for 10 min at room temperature. The labeled products were then purified by anion exchange resin. The purified (99m)Tc-LAI in 1.5% NaCl solution was incubated at 4 °C to assess its stability by LPLC. The purified (99m)Tc-LAI was subjected to studies with a clinically used nebulizer (PARI eFlow®) and the Anderson Cascade Impactor (ACI). The use of ascorbic acid at 0.91 mM resulted in a quantitative labeling efficiency. The LPLC profile showed that the liposomal peak of LAI detected by a UV monitor at both 200 nm and 254 nm overlapped with the radioactivity peak of (99m)Tc-LAI, indicating that (99m)Tc-LAI is suitable for tracing LAI. The ACI study demonstrated that the aerosol droplet size distribution determined gravimetrically was similar to that determined by radioactivity. The liposome surface labeling method using SnCl₂ in 0.91 mM ascorbic acid produced (99m)Tc-LAI with a high labeling efficiency and stability that are adequate to evaluate the deposition and clearance of inhaled LAI in the lung by gamma scintigraphy.

背景与目标： ：脂质体表面的放射性标记可能是体内追踪治疗性载药脂质体的有用工具。我们研究了带有（99m）Tc的放射性标记治疗药物（即抗生素，丁胺卡那霉素）负载的脂质体，（99m）Tc标记的脂质体丁胺卡那霉素吸入剂（（99m）Tc-LAI）的雾化特性，以及通过尺寸排阻法的稳定性高压液相色谱（LPLC）。在室温下，使用溶解在抗坏血酸中的SnCl2作为还原剂，使LAI与（99m）Tc反应10分钟。然后通过阴离子交换树脂纯化标记的产物。将纯化的（99m）Tc-LAI溶于1.5％NaCl溶液，于4°C孵育，以通过LPLC评估其稳定性。纯化的（99m）Tc-LAI用临床使用的雾化器（PARIeFlow®）和Anderson级联撞击器（ACI）进行了研究。 0.91 mM的抗坏血酸的使用导致定量标记效率。 LPLC图谱表明，由UV监测仪在200 nm和254 nm处检测到的LAI脂质体峰与（99m）Tc-LAI的放射性峰重叠，表明（99m）Tc-LAI适合于追踪LAI。 ACI研究表明，通过重量分析确定的气溶胶液滴尺寸分布与通过放射性确定的液滴尺寸分布相似。使用SnCl 2在0.91 mM抗坏血酸中制备的脂质体表面标记法（99m）Tc-LAI具有很高的标记效率和稳定性，足以评估γ闪烁显像法在肺中吸入的LAI的沉积和清除。

BACKGROUND & AIMS: :The patch-clamp technique was used to examine the plasma membranes of sensitive yeast spheroplasts exposed to partially purified killer toxin preparations. Asolectin liposomes in which the toxin was incorporated were also examined. Excised inside-out patches from these preparations often revealed at 118 pS conductance appearing in pairs. The current through this conductance flickered rapidly among three states: dwelling mostly at the unit-open state, less frequently at the two-unit-open state, and more rarely at the closed state. Membrane voltages from -80 to 80 mV had little influence on the opening probability. The current reversed near the equilibrium potential of K+ in asymmetric KCl solutions and also reversed near O mV at symmetric NaCl vs. KCl solutions. The two levels of the conductance were likely due to the toxin protein, as treatment of spheroplasts or liposomes with extracellular protein preparations from isogenic yeasts deleted for the toxin gene gave no such conductance levels. These results show that in vivo the killer-toxin fraction can form a cation channel that seldom closes regardless of membrane voltage. We suggest that this channel causes the death of sensitive yeast cells.

背景与目标： ：使用膜片钳技术检查暴露于部分纯化的杀伤性毒素制剂的敏感酵母原生质球的质膜。还检查了其中掺入了毒素的Asolectin脂质体。从这些制剂中切出的由内而外的补丁通常以118 pS的电导率成对出现。通过该电导的电流在三个状态之间快速闪烁：主要在单元打开状态下居住，在两个单元打开状态下较少居住，而在闭合状态下很少居住。从-80到80 mV的膜电压对打开概率几乎没有影响。在非对称KCl溶液中，电流在K的平衡电位附近反转，并且在对称NaCl与KCl溶液中，在O mV附近也反转。电导的两个水平可能是由于毒素蛋白引起的，因为用针对毒素基因缺失的等基因酵母中的胞外蛋白制剂处理原生质球或脂质体并没有得到这样的电导水平。这些结果表明，在体内，无论膜电压如何，杀伤毒素部分都可以形成很少关闭的阳离子通道。我们建议该通道导致敏感酵母细胞死亡。

BACKGROUND & AIMS: :Epidermal growth factor receptor (EGFR) is overexpressed in a wide range of solid tumors. In this study, we exploited a high-affinity EGFR-antagonistic affibody (ZEGFR) coupled to a doxorubicin loaded pegylated liposome (LS-Dox) for concurrent passive and active targeting of EGFR+ A431 tumor cells in vitro and in vivo. The in vitro studies revealed that the Dox liposomes coupled with ZEGFR (AS-Dox) showed a higher Dox uptake than LS-Dox in EGFR+ A431 cells but not in EGFR- B16F10 cells, resulting in a selectively enhanced cytotoxicity. In vivo, AS-Dox confirmed its long circulation time and efficient accumulation in tumors. This targeted chemotherapy achieved greater tumor suppression. Further, this low-dose but effective targeted treatment reduced systemic toxicity such as body weight loss and organ injury demonstrated by H&E staining. Thus, selective targeting of LS-Dox coupled with ZEGFR enhanced antitumor effects and improved systemic safety. These results demonstrated that LS-Dox coupled with ZEGFR might be developed as a potential tool for therapy of EGFR+ tumors.

背景与目标： ：表皮生长因子受体（EGFR）在多种实体瘤中过表达。在这项研究中，我们利用高亲和力的EGFR拮抗抗体（ZEGFR）与负载阿霉素的聚乙二醇化脂质体（LS-Dox）结合，在体内外对EGFR A431肿瘤细胞进行被动和主动靶向。体外研究表明，在EGFR A431细胞中，Dox脂质体与ZEGFR（AS-Dox）的结合比LS-Dox表现出更高的Dox摄取，而在EGFR- B16F10细胞中则没有，而导致了选择性的细胞毒性。在体内，AS-Dox证实了其长的循环时间和在肿瘤中的有效积累。该靶向化学疗法实现了更大的肿瘤抑制。此外，这种低剂量但有效的靶向治疗降低了全身毒性，例如H＆E染色证明了体重减轻和器官损伤。因此，选择性靶向LS-Dox并结合ZEGFR可增强抗肿瘤作用并改善全身安全性。这些结果表明，LS-Dox结合ZEGFR可能被开发为治疗EGFR肿瘤的潜在工具。

BACKGROUND & AIMS: :Ciprofloxacin (CPFX) containing therapeutic systems were developed using gel- and liposome-based formulations to minimize tear-driven dilution in the conjunctival sac, a long-pursued objective in ophthalmology. Physicochemical properties (pH, osmolarity, viscosity, expansivity, membrane fluidity and in vitro CPFX release rate) of the preparations were studied by the appropriate methods. For gel preparation, the bio-adhesive poly(vinyl alcohol) and polymethacrylic acid derivatives were applied in various concentrations. In our liposome-supported carrier systems, multilamellar vesicles from lecithin and alpha-L-dipalmithoyl-phosphatidylcholine provided the encapsulating agent. Electron paramagnetic resonance (EPR) spectroscopy was applied to study the molecular interactions in the ophthalmic formulations. The polymer hydrogels used in our preparations ensured a steady and prolonged active ingredient release. In addition, encapsulation of the CPFX into liposomes prolonged the in vitro release of the antibacterial agent depending on the lipid composition of the vesicles.

背景与目标： ：含有环丙沙星（CPFX）的治疗系统是使用基于凝胶和脂质体的制剂开发的，以最大程度地减少眼结膜囊中眼泪驱动的稀释作用，结膜囊是眼科长期以来追求的目标。通过适当的方法研究了制剂的理化性质（pH，摩尔渗透压浓度，粘度，膨胀性，膜流动性和体外CPFX释放速率）。为了制备凝胶，以各种浓度施加生物粘附性聚乙烯醇和聚甲基丙烯酸衍生物。在我们的脂质体支持的载体系统中，卵磷脂和α-L-二棕榈酰-磷脂酰胆碱的多层囊泡提供了包封剂。电子顺磁共振（EPR）光谱用于研究眼科制剂中的分子相互作用。我们制剂中使用的聚合物水凝胶可确保稳定和延长活性成分的释放。另外，取决于囊泡的脂质组成，将CPFX包封到脂质体中延长了抗菌剂的体外释放。

BACKGROUND & AIMS: :Liposomes loaded with lactosyl-norcantharidin phospholipid complex (LPC) were prepared, in which soybean phosphatidylcholine was used to improve the liposolubility of lactosyl-norcantharidin (Lac-NCTD). The pH-sensitive LPC liposomes (pH-LPC-lips) were obtained by electrostatic adsorption of the carboxymethyl chitosan onto the surface of the liposomes. The in vitro drug release of pH-LPC-lips and LPC-lips was investigated in dissolution media with pH ranging from 1.0 to 8.0. The in vitro antitumor activity and cellular uptake of Lac-NCTD and its liposomes to HepG2 cells were studied. The pH-LPC-lips demonstrated strong cytotoxicity against the cells and easily permeated the cell membrane. The in vivo antitumor activities of Lac-NCTD and its liposomes were evaluated in mice bearing H22 liver tumors. The pH-LPC-lips displayed the best tumor inhibitory effect. The optical imaging results indicated that Cy7- labeled pH-LPC-lips showed excellent hepatocyte specificity in H22 tumor-bearing mice. Therefore, pH-LPC-lips can be regarded as liver-targeting agents that combine targeting and active releasing.

背景与目标： ：制备了负载有乳糖基-降冰片素磷脂复合物（LPC）的脂质体，其中大豆磷脂酰胆碱用于改善乳糖基-降冰片素（Lac-NCTD）的脂溶性。 pH敏感的LPC脂质体（pH-LPC脂质）是通过将羧甲基壳聚糖静电吸附到脂质体表面上而获得的。在pH范围为1.0至8.0的溶出介质中研究了pH-LPC-lips和LPC-lips的体外药物释放。研究了Lac-NCTD及其脂质体对HepG2细胞的体外抗肿瘤活性和细胞摄取。 pH-LPC嘴唇对细胞表现出强大的细胞毒性，并容易渗透到细胞膜上。在携带H22肝肿瘤的小鼠中评估了Lac-NCTD及其脂质体的体内抗肿瘤活性。 pH-LPC-嘴唇显示出最佳的肿瘤抑制作用。光学成像结果表明，Cy7标记的pH-LPC嘴唇在荷H22荷瘤小鼠中显示出优异的肝细胞特异性。因此，pH-LPC-嘴唇可被视为结合靶向和主动释放的肝脏靶向剂。

BACKGROUND & AIMS: OBJECTIVE:The aim of this study is to establish the dexamethasone sodium phosphate multivesicular liposomes thermosensative hydrogel (DEX-MVLs-Gel) drug delivery system and to analyze the pharmacodynamics, pharmacokinetics and safety of DEX-MVLs-Gel as well as to explore whether the prepared DEX-MVLs-Gel can protect the hearing in the guinea pigs following noise exposure. METHODS:DEX-MVLs formulations were constructed by double emulsion method, and the DEX-MVLs-Gel was prepared after adding P407 and P188 into the DEX-MVLs. A total of 20 adult albino guinea pigs were chosen to establish the animal models with noise-induced hearing loss. After animals were treated with DEX-MVLs-Gel at concentrations of 20, 6 and 2 mg/mL, and 5 mg/mL Dexamethasone Sodium Phosphate (DEX-P) solution, respectively, the hearing function, drug concentration in the peripheral lymph fluid, and hair cell morphology were assessed. RESULTS:The ABR threshold of the 20 mg/mL DEX-MVLs-Gel treated group at the frequencies of 4, 8, 16 and 24 kHz were measured as 47.5 ± 5.2, 48.3 ± 4.1, 55.8 ± 3.8 and 57.5 5 ± 5.2 dB SPL, respectively. Statistical significances were noted between the 20 mg/mL DEX-MVLs-Gel treated group and control group at each frequency (all P < 0.05), between the 2 mg/mL and 6 mg/mL DEX-MVLs-Gel treated groups at the frequencies of 4 and 8 kHz (both P < 0.05). High Performance Liquid Chromatography (HPLC) demonstrated that the drug concentrations in the peripheral lymph in all groups were gradually decreased on the 1st, 3rd and 7th d after intratympanic injection. Scattered hair cell loss could be observed mainly in the basal and middle turn in the saline administrated group and the 20 mg/mL DEX-MVLs-Gel administration group, and the hair cell loss was not identified in the apical turn. CONCLUSIONS:A high concentration (20 mg/mL) of DEX-MVLs-Gel exerts significant protective effects upon the guinea pigs with noise-induced hearing loss. The prepared DEX-MVLs-Gel can be effectively maintained in the peripheral lymph fluid of guinea pigs for 3-7 d and MVLs-Gel causes no obvious ototoxicity.

背景与目标： 目的：本研究的目的是建立地塞米松磷酸钠多囊脂质体热敏水凝胶（DEX-MVLs-Gel）给药系统，并分析DEX-MVLs-Gel的药效学，药代动力学和安全性，并探讨是否制备的DEX-MVLs-Gel可以在噪声暴露后保护豚鼠的听力。
方法：采用双乳化法制备DEX-MVLs制剂，并在PEX-MVLs中加入P407和P188制备DEX-MVLs-Gel。总共选择了20只成年的白化豚鼠，以建立噪声引起的听力损失的动物模型。用浓度分别为20、6和2 mg / mL和5 mg / mL的地塞米松磷酸钠（DEX-P）溶液的DEX-MVLs-Gel处理动物后，听力功能和外周淋巴液中的药物浓度，并评估了毛细胞形态。
结果：20 mg / mL DEX-MVLs-Gel治疗组在4、8、16和24kHz频率下的ABR阈值分别为47.5±5.2、48.3±4.1、55.8±3.8和57.5 5±5.2 dB分别为SPL。在各频率下，在20 mg / mL DEX-MVLs-Gel治疗组和对照组之间，在2 mg / mL和6 mg / mL DEX-MVLs-Gel治疗组之间的统计学显着性在所有频率下（所有P <0.05）。频率为4和8 kHz（均为P <0.05）。高效液相色谱法（HPLC）显示，在鼓膜内注射后第1、3和7天，所有组的外周淋巴中的药物浓度均逐渐降低。盐水给药组和20 mg / mL DEX-MVLs-Gel给药组的散发性毛细胞丢失主要发生在基底和中部回旋处，而在心尖回旋中未发现毛细胞丢失。
结论：高浓度（20 mg / mL）的DEX-MVLs-Gel对豚鼠具有噪声诱发的听力损失具有明显的保护作用。制备的DEX-MVLs-Gel可以有效地保持在豚鼠的外周淋巴液中3-7天，而MVLs-Gel不会引起明显的耳毒性。

BACKGROUND & AIMS: :Polymer-associated infections are a major problem in implanted or intravascular devices. Among others, microorganisms of the staphylococcal family have been identified as the most important culprit. Prevention of bacterial adhesion and colonization of polymeric surfaces by release of antimicrobial agents incorporated into the polymers itself are currently under study. We have developed a novel method for the functionalization of a polymeric surface which is based on the deposition of covalently coupled lipid structures from antibiotic loaded vesicles. We have found that such process significantly reduces the bacterial growth on polystyrene material. In this work, lipid coverage obtained from multilamellar (MLVs) and extruded unilamellar (LUVs) vesicles were analyzed with respect to their adhesion efficiency on three types of polystyrene (PS) well-plates. Two methods of lipid deposition were characterized and compared in terms of surface lipid density and time stability: deposition of cationic vesicles on negatively charged surfaces and formation of covalent linkages between functionalized lipids and amines enriched surfaces. In order to study the antibiotic encapsulation efficiency we measured how the rifampicin (RIF) loading was affected by changes of liposome charge upon introduction of various amounts of stearylamine (SA), distearoyl-trimethylammonium propane (DSTAP) or dioleoyloxypropyl-trimethylammonium chloride (DOTAP) into the liposomal formulation. RIF-coated polymeric surfaces were also tested against a Staphylococcus epidermidis strain to evaluate their efficacy in vitro, showing that only approximately 2% of such bacteria inoculated on MLV-treated PS substrate were able to proliferate. Covalently immobilized lipid films showed about a tenfold increase in time stability compared to electrostatically bonded lipid films. Furthermore, substrates covalently modified with RIF-loaded MLVs retained an antibacterial activity for up to 12 days when aged in buffer at 37 degrees C. Such antimicrobial polymer coatings show promise for their use as antibacterial barrier for the prevention of catheter-related infections.

背景与目标： ：与聚合物相关的感染是植入式或血管内装置的主要问题。其中，葡萄球菌家族的微生物已被确定为最重要的罪魁祸首。目前正在研究通过释放掺入到聚合物本身中的抗微生物剂来防止细菌粘附和聚合物表面定居。我们已经开发了一种用于聚合物表面功能化的新方法，该方法基于从载有抗生素的囊泡中共价偶联的脂质结构的沉积。我们已经发现，这种方法显着减少了细菌在聚苯乙烯材料上的生长。在这项工作中，分析了从多层（MLV）和单层挤出（LUV）囊泡获得的脂质覆盖度，分析了它们在三种类型的聚苯乙烯（PS）孔板上的粘附效率。表征了两种脂质沉积的方法，并根据表面脂质密度和时间稳定性进行了比较：阳离子小泡在带负电荷的表面上的沉积以及功能化脂质和富含胺的表面之间形成共价键。为了研究抗生素的包封效率，我们测量了引入各种量的硬脂胺（SA），二硬脂酰三甲基铵丙烷（DSTAP）或二油酰氧基丙基三甲基氯化铵（DOTAP）时脂质体电荷的变化如何影响利福平（RIF）的负载量进入脂质体制剂。还用RIF涂层的聚合物表面针对表皮葡萄球菌菌株进行了测试，以在体外评估其功效，结果表明，仅约2％的此类细菌接种在MLV处理的PS底物上能够繁殖。与静电结合的脂质膜相比，共价固定的脂质膜显示出约10倍的时间稳定性。此外，当在37摄氏度的缓冲液中老化时，用RIF负载的MLV共价修饰的底物在长达12天的时间内仍保留了抗菌活性。此类抗菌聚合物涂层有望将其用作预防导管相关感染的抗菌屏障。

BACKGROUND & AIMS: :Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) play a key role in membrane fusion in the secretory pathway. In vitro, SNAREs spontaneously assemble into helical SNARE complexes with the transmembrane domains at the C-terminal end. During fusion, SNAREs are thought to bridge the two membranes and assemble in a zipper-like fashion, pulling the membranes together and initiating fusion. However, it is not clear to what extent SNARE assembly contributes to membrane attachment and membrane fusion. Using the neuronal SNAREs synaptobrevin (VAMP), SNAP-25, and syntaxin as examples, we show here that liposomes containing synaptobrevin firmly attach to planar surfaces containing immobilized syntaxin. Attachment requires the formation of SNARE complexes because it is dependent on the presence of SNAP-25. Binding is competed for by soluble SNARE fragments, with noncognate SNAREs such as endobrevin (VAMP8), VAMP4, and VAMP7 (Ti-VAMP) being effective but less potent in some cases. Furthermore, although SNAP-23 is unable to substitute for SNAP-25 in the attachment assay, it forms complexes of comparable stability and is capable of substituting in liposome fusion assays. Vesicle attachment is initiated by SNARE assembly at the N-terminal end of the helix bundle. We conclude that SNAREs can indeed form stable trans-complexes that result in vesicle attachment if progression to fusion is prevented, further supporting the zipper model of SNARE function.

背景与目标： ：可溶性N-乙基马来酰亚胺敏感因子附着蛋白受体（SNARE）在分泌途径的膜融合中起关键作用。在体外，SNARE自发组装成螺旋状的SNARE复合物，在C末端带有跨膜结构域。在融合过程中，SNARE被认为桥接了两个膜并以拉链状的方式组装，将膜拉在一起并开始融合。但是，尚不清楚SNARE组装在多大程度上有助于膜的附着和融合。以神经元SNAREs突触短纤维蛋白（VAMP），SNAP-25和语法素为例，我们在这里显示了含有突触短纤维蛋白的脂质体牢固地附着在含有固定化语法素的平面上。附着需要形成SNARE复合物，因为它取决于SNAP-25的存在。可溶性的SNARE片段竞争结合，其中非同源的SNARE（例如内皮素（VAMP8），VAMP4和VAMP7（Ti-VAMP））有效，但在某些情况下效力较弱。此外，尽管SNAP-23在附着测定中无法替代SNAP-25，但它形成了具有相当稳定性的复合物，并能够替代脂质体融合测定。囊泡的附着是由螺旋束N端的SNARE组装引发的。我们得出的结论是，如果防止融合进展，SNARE确实可以形成稳定的反式复合物，从而导致囊泡附着，从而进一步支持SNARE功能的拉链模型。

BACKGROUND & AIMS: :Reaction centers of the phototrophic bacterium Rhodopseudomonas palustris were introduced as proton motive force-generating systems in membrane vesicles of two anaerobic bacteria. Liposomes containing reaction center-light-harvesting complex I pigment protein complexes were fused with membrane vesicles of Streptococcus cremoris or Clostridium acetobutylicum by freeze-thawing and sonication. Illumination of these fused membranes resulted in the generation of a proton motive force of approximately -110 mV. The magnitude of the proton motive force in these membranes could be varied by changing the light intensity. As a result of this proton motive force, amino acid transport into the fused membranes could be observed. The initial rate of leucine transport by membrane vesicles of S. cremoris increased exponentially with the proton motive force. An H+/leucine stoichiometry of 0.8 was determined from the steady-state level of leucine accumulation and the proton motive force, and this stoichiometry was found to be independent of the magnitude of the proton motive force. These results indicate that the introduction of bacterial reaction centers in membrane vesicles by the fusion procedure yields very attractive model systems for the study of proton motive force-consuming processes in membrane vesicles of (strict) anaerobic bacteria.

背景与目标： ：在两种厌氧细菌的膜囊泡中引入了光养细菌Phodopseudomonas palustris的反应中心作为质子动力产生系统。通过冷冻-解冻和超声处理，将含有反应中心-光收集复合物I色素蛋白复合物的脂质体与Cremoococcus cremoris或Clostodium acetobutylicum的膜囊泡融合。这些融合膜的照明导致产生约-110 mV的质子原动力。这些膜中质子原动力的大小可以通过改变光强度来改变。由于该质子原动力，可以观察到氨基酸转运到融合膜中。 Cremoris膜小泡中亮氨酸转运的初始速率随质子动力呈指数增加。从亮氨酸积累的稳态水平和质子原动力确定H /亮氨酸化学计量为0.8，并且发现该化学计量与质子原动力的大小无关。这些结果表明通过融合程序在膜囊泡中引入细菌反应中心产生了非常有吸引力的模型系统，用于研究（严格）厌氧细菌的膜囊泡中的质子原动力消耗过程。

BACKGROUND & AIMS: :Hyaluronic acid liposomal gels have previously demonstrated in vivo their great potential for drug delivery. Elucidating their phase behavior and structure would provide a better understanding of their use properties. This work evaluates the microstructure and the phase behavior of mixtures of hyaluronic acid (HA) and liposomes and their impact on the vesicle mobility. HA concentration and surface properties of liposomes (positively or negatively charged, neutral, with a polyethylene glycol corona) are varied while the liposome concentration remains constant. Below the entanglement concentration of HA (0.4%), the mixtures exhibit a depletion phase separation except for positively charged liposomes that interact with anionic HA through attractive electrostatic interactions. At high HA concentration, no macroscopic phase separation is observed, except a slight syneresis with cationic liposomes. The microstructure shows aggregates of liposomes homogeneously distributed into a HA network except for PEGylated liposomes, which seem to form bicontinuous interpenetrating networks. The diffusion of liposomes is controlled by HA concentration and their surface properties. Finally, PEGylated liposomes display the highest mobility at high HA concentration (2.28%) both macro- and microscopically. The microstructure of HA-liposomes mixtures and the diffusion of liposomes are key parameters that must be taken into account for drug delivery.

背景与目标： 玻尿酸脂质体凝胶先前已在体内证明了其巨大的药物输送潜力。阐明它们的相行为和结构将更好地了解它们的使用特性。这项工作评估透明质酸（HA）和脂质体的混合物的微观结构和相行为及其对囊泡迁移率的影响。脂质体（带有聚乙二醇电晕的正电荷或负电荷，中性）的HA浓度和表面性质发生变化，而脂质体浓度保持恒定。低于HA的纠缠浓度（0.4％），混合物显示耗尽相分离，除了带正电荷的脂质体通过吸引性的静电相互作用与阴离子HA相互作用。在高HA浓度下，除了与阳离子脂质体轻微的脱水收缩外，没有观察到宏观的相分离。微观结构显示脂质体的聚集体均匀分布到HA网络中，但聚乙二醇化脂质体似乎形成了双连续的互穿网络。脂质体的扩散受HA浓度及其表面性质控制。最后，聚乙二醇化脂质体在高HA浓度下（2.28％）在宏观和微观上均显示出最高的迁移率。 HA-脂质体混合物的微观结构和脂质体的扩散是药物递送必须考虑的关键参数。

BACKGROUND & AIMS: :Phospholipid exchange protein from beef heart or beef liver does not catalyze the transfer of phosphatidylcholine from multilamellar vesicles of phosphatidylcholine. Certain combinations of phospholipids, however, do yield multilamellar vesicles that will exchange phosphatidylcholine with liposomes in the presence of exchange protein. Multilamellar vesicles of phosphatidylcholine:phosphatidylethanolamine:cardiolipin (70:25:5, mol%) can be used in place of mitochondria or erythrocyte ghosts as an improved acceptor particle in the study of liposome structure with phospholipid exchange proteins. These multilamellar vesicles act as a well-defined reservoir of unlabeled phosphatidylcholine with 7% exchangable phospholipid. When the distribution of phosphatidylcholine in liposomes is studied by the exchange protein technique, results can be influence by the choice of phospholipid acceptor particle. With mitochondria as acceptor particle, the percentage of phosphatidylcholine in the outer monolayer of a liposome appears to be 60%, whereas a value of 70% is obtained when multilamellar vesicles are the acceptor. The discrepancy can be explained by a heterogeneity in liposomes prepared by sonication. A size-dependent fusion or adsorption process occurs between liposomes and mitochondria; the very small liposomal vesicles, obtained by gel filtration, combine nearly quantitatively with the natural membrane. This phenomenon is not seen with multilamellar vesicles. Thus by using multilamellar vesicles one obtains a less biased estimate of phospholipid distribution between inner and outer layers of liposomes.

背景与目标： ：来自牛肉心或牛肉肝的磷脂交换蛋白不能催化磷脂酰胆碱的多层囊泡中磷脂酰胆碱的转移。然而，磷脂的某些组合确实会产生多层囊泡，该多层囊泡将在存在交换蛋白的情况下与脂质体交换磷脂酰胆碱。磷脂酰胆碱：磷脂酰乙醇胺：心磷脂（70：25：5，mol％）的多层囊泡可代替线粒体或红细胞幻影用作研究磷脂交换蛋白脂质体结构的改良受体颗粒。这些多层囊泡充当明确定义的未标记磷脂酰胆碱的储库，磷脂酰胆碱具有7％的可交换磷脂。当通过交换蛋白技术研究磷脂酰胆碱在脂质体中的分布时，结果会受到磷脂受体颗粒的选择的影响。用线粒体作为受体颗粒，脂质体的外单层中的磷脂酰胆碱的百分比似乎为60％，而当多层囊泡为受体时获得的值为70％。差异可以通过超声处理制备的脂质体中的异质性来解释。脂质体和线粒体之间发生大小依赖的融合或吸附过程。通过凝胶过滤获得的非常小的脂质体囊泡几乎与天然膜定量结合。这种现象在多层囊泡中看不到。因此，通过使用多层囊泡，人们获得了脂质体内层和外层之间磷脂分布的偏差较小的估计。

BACKGROUND & AIMS: :Previously we reported that fusogenic liposomes, prepared by fusing simple liposomes with Sendai virus particles, could introduce their contents directly and efficiently into the cytoplasm. In this study, we examined the anti-tumour activity of fusogenic liposomes containing fragment A of diphtheria toxin (DTA). Fusogenic liposomes containing DTA showed high cytotoxicity against sarcoma-180 (S-180) cells in vitro. When these liposomes were administered into the abdominal cavity of ddY mice carrying S-180, tumour cells completely disappeared in four of six tumour-bearing mice without decrease in body weight. Neither simple liposomes containing DTA nor empty fusogenic liposomes had any effect on tumour suppression. We conclude that fusogenic liposomes containing DTA are new and potentially effective tools for the treatment of ascites tumours without any severe side-effects.

背景与目标： ：以前，我们报道过通过将简单脂质体与仙台病毒颗粒融合而制备的融合脂质体可以将其内容物直接有效地引入细胞质中。在这项研究中，我们检查了含有白喉毒素（DTA）片段A的融合脂质体的抗肿瘤活性。含有DTA的融合脂质体在体外显示出对肉瘤180（S-180）细胞的高细胞毒性。当将这些脂质体施用于携带S-180的ddY小鼠的腹腔中时，六只荷瘤小鼠中的四只肿瘤细胞完全消失，而体重却没有减少。含有DTA的简单脂质体和空的融合脂质体均未对肿瘤抑制产生任何影响。我们得出的结论是，含有DTA的融合脂质体是治疗腹水肿瘤的新型且潜在有效的工具，没有任何严重的副作用。

BACKGROUND & AIMS: :The aim of the present study was the in vivo evaluation of thiomer-coated liposomes for an oral application of peptides. For this purpose, salmon calcitonin was chosen as a model drug and encapsulated within liposomes. Subsequently, the drug loaded liposomes were coated with either chitosan-thioglycolic acid (CS-TGA) or an S-protected version of the same polymer (CS-TGA-MNA), leading to an increase in the particle size of about 500 nm and an increase in the zeta potential from approximately -40 mV to a maximum value of about +44 mV, depending on the polymer. Coated liposomes were demonstrated to effectively penetrate the intestinal mucus layer where they came in close contact with the underlying epithelium. To investigate the permeation enhancing properties of the coated liposomes ex vivo, we monitored the transport of fluoresceinisothiocyanate-labeled salmon calcitonin (FITC-sCT) through rat small intestine. Liposomes coated with CS-TGA-MNA showed the highest effect, leading to a 3.8-fold increase in the uptake of FITC-sCT versus the buffer control. In vivo evaluation of the different formulations was carried out by the oral application of 40 μg of sCT per rat, either encapsulated within uncoated liposomes, CS-TGA-coated liposomes or CS-TGA-MNA-coated liposomes, or given as a solution serving as negative control. The blood calcium level was monitored over a time period of 24h. The highest reduction in the blood calcium level, to a minimum of 65% of the initial value after 6h, was achieved for CS-TGA-MNA-coated liposomes. Comparing the areas above curves (AAC) of the blood calcium levels, CS-TGA-MNA-coated liposomes led to an 8.2-fold increase compared to the free sCT solution if applied orally in the same concentration. According to these results, liposomes coated with S-protected thiomers have demonstrated to be highly valuable carriers for enhancing the oral bioavailability of salmon calcitonin.

背景与目标： ：本研究的目的是体内评价巯基聚合物包衣的脂质体用于肽的口服应用。为此，鲑鱼降钙素被选作模型药物并封装在脂质体内。随后，用壳聚糖-巯基乙酸（CS-TGA）或同一聚合物的S-保护形式（CS-TGA-MNA）涂覆载有药物的脂质体，导致粒径增加约500 nm，并且取决于聚合物，ζ电位从约-40 mV增加到约44 mV的最大值。已证明包衣脂质体可有效渗透肠道粘液层，并与下面的上皮细胞紧密接触。为了研究离体包覆脂质体的渗透增强特性，我们监测了荧光素异硫氰酸酯标记的鲑鱼降钙素（FITC-sCT）通过大鼠小肠的运输。与缓冲液对照相比，涂有CS-TGA-MNA的脂质体显示出最高的作用，导致FITC-sCT的摄取增加了3.8倍。通过口服每只大鼠40μgsCT来对不同制剂进行体内评估，将其包裹在未包被的脂质体，CS-TGA包被的脂质体或CS-TGA-MNA包被的脂质体内，或以溶液形式提供作为阴性对照。在24小时内监测血钙水平。对于CS-TGA-MNA涂层脂质体，血钙水平最高降低至6h后至少达到初始值的65％。比较血液钙水平的曲线上方区域（AAC），如果以相同浓度口服施用，与游离sCT溶液相比，CS-TGA-MNA包衣的脂质体导致增加了8.2倍。根据这些结果，用S-保护的硫代聚合物包衣的脂质体已被证明是用于提高鲑鱼降钙素的口服生物利用度的极有价值的载体。

BACKGROUND & AIMS: :Cationic liposomes can efficiently carry nucleic acids into mammalian cells. This property is tightly connected with their ability to fuse with negatively charged natural membranes (i.e. the plasma membrane and endosomal membrane). We used FRET to monitor and compare the efficiency of lipid mixing of two liposomal preparations--one of short-chained diC14-amidine and one of long-chained unsaturated DOTAP--with the plasma membrane of HeLa cells. The diC14-amidine liposomes displayed a much higher susceptibility to lipid mixing with the target membranes. They disrupted the membrane integrity of the HeLa cells, as detected using the propidium iodide permeabilization test. Morphological changes were transient and essentially did not affect the viability of the HeLa cells. The diC14-amidine liposomes were much more effective at either inducing lipid mixing or facilitating transfection.

背景与目标： ：阳离子脂质体可以有效地将核酸带入哺乳动物细胞。这种特性与其与带负电的天然膜（即质膜和内体膜）融合的能力紧密相关。我们使用FRET监测和比较两种脂质体制剂（一种短链diC14--和一种长链不饱和DOTAP）与HeLa细胞质膜的脂质混合效率。 diC14-am脂质体对脂质与靶膜混合表现出更高的敏感性。使用碘化丙啶通透性测试检测到，它们破坏了HeLa细胞的膜完整性。形态变化是短暂的，基本上不影响HeLa细胞的生存能力。 diC14-am脂质体在诱导脂质混合或促进转染方面更为有效。

BACKGROUND & AIMS: PURPOSE:Intravitreal antivascular endothelial growth factor (anti-VEGF) application has revolutionized the treatment of choroidal neovascularization (CNV), a hallmark of wet age-related macular degeneration. However, additional treatment options are desirable as not all CNV lesions respond to anti-VEGF injections. Here, we assessed the feasibility of targeted delivery of cationic liposome-encapsulated paclitaxel (EndoTAG-1) in treating CNV. Furthermore, we investigated whether a new formulation of verteporfin encapsulated in cationic liposomes (CL-VTP) enhances the effect of photodynamic therapy (PDT). METHODS:EndoTAG-1, LipoSPA, and CL-VTP were produced by encapsulating paclitaxel, succinyl-paclitaxel, or verteporfin in cationic liposomes (CL). Mice underwent argon laser coagulations at day 0 (D0) to induce CNV. EndoTAG-1 and LipoSPA were injected into the tail vein at D1, D3, D5, D7, and D9. Taxol, CL, or trehalose buffer alone was injected in control animals. At D10, all animals were perfused with fluorescein isothiocyanate (FITC)-dextran. Flatmounts comprising the retinal pigment epithelium, choroid, and sclera were prepared for quantifying the CNV by measuring the area of lesions perfused with FITC-dextran. For PDT, mice received an injection with CL-VTP or Visudyne at D10. One eye was treated with PDT while the other served as a control. Evaluation of RPE-choroid-scleral and retinal flatmounts was performed at D12, D14, or D17. Perfusion with FITC-dextran and tetramethylrhodamine-5-(and 6)-isothiocyanate-lectin staining was used to distinguish between perfused and non-perfused choroidal vessels. RESULTS:EndoTAG-1 or LipoSPA significantly reduced CNV size to 15% compared to trehalose controls. The mean CNV area of mice treated with CL was reduced (though not significantly) to about one-half of the value of the trehalose control group. The same was observed for paclitaxel. Thus, the reduction in the CNV size between treatment with CL and treatment with EndoTAG-1 or LipoSPA was 40%, which was not significant. PDT using either CL-VTP or Visudyne reduced CNV size to 65% (D17) of trehalose control size. CNV size was further diminished to 56% with Visudyne and 53% with CL-VTP when PDT was repeated twice. Most importantly, PDT-associated retinal damage was less pronounced using CL-VTP compared to Visudyne. CONCLUSIONS:Systemic intravenous injection of paclitaxel (EndoTAG-1)- or succinyl-paclitaxel (LipoSPA)-loaded CL had a significant antiangiogenic effect in a CNV mouse model. PDT with CL-VTP was as effective as Visudyne in neovascular obliteration but induced less tissue damage. Our data suggest that systemic application of cationic liposome formulations may serve to treat ocular neovascular diseases. This approach may reduce the need for intraocular injections and may benefit patients with neovascular lesions irresponsive to anti-VEGF treatment.

背景与目标： 目的：玻璃体内抗血管内皮生长因子（anti-VEGF）的应用彻底改变了脉络膜新生血管（CNV）的治疗方法，脉络膜新生血管是湿性年龄相关性黄斑变性的标志。但是，由于并非所有的CNV病变都对抗VEGF注射产生反应，因此需要其他治疗选择。在这里，我们评估了靶向脂质体包裹的紫杉醇（EndoTAG-1）靶向治疗CNV的可行性。此外，我们调查了封装在阳离子脂质体（CL-VTP）中的维替泊芬的新配方是否增强了光动力疗法（PDT）的效果。
方法：EndoTAG-1，LipoSPA和CL-VTP是通过将紫杉醇，琥珀酰-紫杉醇或verteporfin包裹在阳离子脂质体（CL）中制成的。在第0天（D0）对小鼠进行氩激光凝结以诱导CNV。将EndoTAG-1和LipoSPA注入D1，D3，D5，D7和D9的尾静脉。在对照动物中单独注射紫杉醇，CL或海藻糖缓冲液。在第10天，向所有动物灌注异硫氰酸荧光素（FITC）-葡聚糖。制备包含视网膜色素上皮，脉络膜和巩膜的扁平支架，以通过测量灌注FITC-右旋糖酐的病变面积来定量CNV。对于PDT，小鼠在D10时接受CL-VTP或Visudyne注射。一只眼用PDT治疗，另一只作为对照。在D12，D14或D17进行RPE脉络膜巩膜和视网膜平片的评估。用FITC-葡聚糖和四甲基罗丹明5-（和6）-异硫氰酸酯-凝集素染色进行灌注以区分灌注的和未灌注的脉络膜血管。
结果：与海藻糖对照组相比，EndoTAG-1或LipoSPA将CNV大小显着降低至15％。用CL治疗的小鼠的平均CNV面积减少（尽管不明显）至海藻糖对照组的一半左右。对于紫杉醇观察到相同的结果。因此，在CL治疗与EndoTAG-1或LipoSPA治疗之间CNV大小的减少为40％，这并不显着。使用CL-VTP或Visudyne的PDT可将CNV大小减小至海藻糖对照大小的65％（D17）。当PDT重复两次时，Visudyne的CNV大小进一步减小至56％，CL-VTP的CNV大小进一步减小至53％。最重要的是，与Visudyne相比，使用CL-VTP的PDT相关性视网膜损伤不那么明显。
结论：全身静脉注射紫杉醇（EndoTAG-1）或琥珀酰紫杉醇（LipoSPA）负载的CL在CNV小鼠模型中具有显着的抗血管生成作用。带有CL-VTP的PDT在新生血管闭塞方面与Visudyne一样有效，但引起的组织损伤较少。我们的数据表明，阳离子脂质体制剂的全身应用可能有助于治疗眼部新血管疾病。这种方法可以减少眼内注射的需要，并且可以使对抗VEGF治疗无反应的新生血管病变患者受益。