Ufasomes as Plausible Carriers for Horizontal Gene Transfer

In this article, we propose ufasomes as carriers for the horizontal transfer of genes from plants. “Ufasome” is an abbreviation for unsaturated fatty acid liposomes, which are generated at specific pH. The formation of ufasomes is believed to occur due to associative interaction in mixtures of fully ionized and unionized fatty acids at pH > 7.0. In past, ufasomes have been widely considered as pre-biotic models for cellular compartments. Using same principles, in the present work, we provide a theoretical treatise presenting ufasomes as carriers for horizontal transfer of engineered genes from plants to either soil-microbes or to environment.     

Development,Characterization, and Evaluation of Liposomes and Niosomes of Bacitracin Zinc

The skin permeation of bacitracin zinc in liposomes and niosomes after topical application were elucidated in the present study with the to increase its penetration capacity and, hence, efficiency. The formulations of bacitracin zinc were prepared by film hydration method and characterized for vesicle shape, size, entrapment efficiency, and drug permeation across rat skin and also evaluated for their stability. Formulation with niosomes demonstrated a better skin permeation potential, sustained release characteristic, and higher stability as compared to liposomes. The ability of liposomes and niosomes to modulate drug delivery makes the two vesicles useful to formulate topical bacitracin zinc.     

pH-Sensitive liposomes with embedded ampholytic derivatives of cholan-24-oic acid

Stimulus-sensitive liposomes have been prepared from zwitterionic dioleoylphosphocholine and ampholytic molecular switches with carboxylic anionic groups and the triazole or isobutylamino cationic ones attached to the opposite ends of the steroid core. When the pH of outer solution was altered from slightly alkaline to slightly acidic, the switches changed their orientation in the liposomal membrane, which induced temporal defects formation and the release of a drug model load. The low-toxic pH-sensitive isobutylamino derivative–dioleoylphosphocholine liposomes demonstrated fast cargo release.     

Solubilizing interactions of octylphenol surfactants with liposomes modeling the stratum corneum lipid composition

 The interaction of a series of polyethoxylated octylphenols (ethylene oxide units average 8.5–20.0) with liposomes modeling the stratum corneum (SC) lipid composition (40% ceramides, 25% cholesterol, 25% palmitic acid and 10% of cholesteryl sulfate) was investigated. The surfactant/lipid molar ratios (Re) and the bilayer/aqueous-phase partition coefficients (K) were determined by monitoring the changes in the static light scattering of the system during solubilization. The fact that free concentration for each surfactant tested was always similar to its critical micelle concentration (CMC) indi-cates that the liposome solubilization was mainly ruled by the formation of mixed micelles. The Re and K para-meters for liposome saturation fell as the surfactant HLB increased. Thus, at this interaction step the higher the surfactant HLB, the higher the ability of these surfactants to saturate SC liposomes and the lower their degree of partitioning into liposomes. However, the maximum solubilizing ability was achieved at intermediate HLB values. Thus, the octylphenols with 20 and 12.5 ethylene oxide units showed, respectively, the highest power of saturation and solubilization of SC structures in terms of the total surfactant amounts needed to produce these effects. Different trends in the interaction of these surfactants with SC liposomes were observed when comparing the Re and K parameters with those reported for PC ones. Thus, whereas the SC liposomes were more resistant to the surfactant action, the affinity of these surfactants with these bilayer structures was higher in all cases. Received: 3 March 1997 Accepted: 22 May 1997     

pH‐sensitive liposome retaining Fe‐porphyrin as SOD mimic for novel anticancer drug delivery system

In this article the novel design of an anticancer drug delivery system is reported based on a pH‐sensitive liposome retaining the Fe‐porphyrin as a superoxide dismutase(SOD) mimic. The liposomes contained cationic/anionic lipid combinations and were composed of Fe‐porphyrin, L ‐α‐phosphatidylcholine (DMPC), dimethylditetradecylammonium bromide (DTDAB), sodispdum oleate (OA_Na), and Tween‐80. The size of the liposome was approximately 30 nm. The EC₅₀ value (the effective concentration of compound required to produce a 50% lethal dose against cells) of the liposome was found to be significantly smaller than that of cisplatin as the control drug, suggesting that the liposome showed a high cytotoxicity toward the cancer cells. This is due to the fact that the pH‐sensitive liposome rapidly corresponds to the acidic environments of the endosomes and is unstable, and the Fe‐porphyrin is delivered into the cytosol. This result suggests that O may be useful as a target molecule to induce the selective death of cancer cells and that a pH‐sensitive liposome retaining Fe‐porphyrin as an SOD mimic is a new class of anticancer agent. Copyright © 2006 John Wiley & Sons, Ltd.     

Thiol‐modified gold‐coated glass as an efficient hydrophobic substrate for drop coating deposition Raman (DCDR) technique

In this paper we report an easy and low‐cost way to prepare a hydrophobic substrate for drop coating deposition Raman (DCDR) spectroscopy. This substrate is formed by a thiol‐modified Au‐coated glass and provides the Raman spectra with the same quality as the commercial Teflon‐coated stainless steel substrate (SpectRIM™, Tienta Sciences, Inc.) for model molecular systems – albumin solution and liposome suspension. Gold layer, similarly to polished steel in the commercial substrate, served as a highly refractive layer strongly increasing the Raman signal. The main advantage of introduced substrate is that it is simple and a low‐cost preparation easily manageable in every standard laboratory. Thus, it represents a promising alternative to commercial Teflon‐coated stainless steel substrate. Copyright © 2016 John Wiley & Sons, Ltd.     

Possibility of Targeting Treatment for Ischemic Heart Disease With Liposome (Ⅰ)

This paper reports the basic research on the possibility of using targeting treatment for ischemic heart disease with liposome as drug carrier. Studies have been performed on isolated rat cardiomyocytes, or isolated perfused rat and rabbit hearts. Results show that cardiomyocytes may interact with liposome through fusion, endocytosis, adsorption and molecular exchange of phospholipid. Forms of cellular uptake of liposome depend chiefly on the physicochemical properties of liposomes. Anoxia changes the pattern of liposome uptake by cardiomyocytes and increases uptake of liposomes. Uptake of liposomes, especially of positively charged liposomes by ischemic myocardium is significantly increased. The quantity of increase of liposome uptake is in the following order: ischemia-reperfusion area>peripheral area of the infarct>non-ischemic area>infarcted area. The above results indicate that liposome as drug carrier might promote the delivery of drug into ischemic myocardium and cardiomyocytes.     

STUDIES ON TRANSPLANTATION OF THE LAMININ RECEPTOR AND ITS ROLES IN EXPERIMENTAL METASTASIS OF MURINE LEWIS LUNG CARCINOMA CELLS

The isolated laminin receptor (LN-R) labeled by ~(125)I was reconstituted into liposomes.~(125)I-LN-R-liposomes and free ~(125)I-LN-R were separated by Sepharose 4B column chromatogra-phy. The LN-R-liposomes showed affinity for laminin (LN) and were capable of binding toimmobilized LN substrate. In order to make transplantation of LN-R, LN-R-liposomes werefused with cultured murine Lewis lung carcinoma cells with the help of polyethylene glycol(PEG) induction. The radiation with the fused cells was not removed by salt sclution. Thebinding of the fused cells enriched in foreign LN-R to LN substrate increased by 87.5%.Furthermore, the murine Lewis lung carcinoma cells with and without transplanted LN-Rwere injected into C_(57)BL/6J mice through tail veins (5×10~5 cells/each mouse)respectively.The mice in the test group died earlier than those in the control group. The total weight oflung tumor in the test group remarkably increased in comparison with those in the controlgroup. The results taken together     

复合荧光CdSe量子点-脂质体的制备与表征

通过脂质体方法成功地将三辛基氧化膦(TOPO)包覆的CdSe发光量子点从非极性有机溶剂转移到生物相容性的水溶液中.分别通过透射电镜(TEM)、荧光Mapping图像,以及光致发光(PL)光谱进行表征.TEM照片显示制备的CdSe核量子点为球形,具有良好的单分散特性,平均粒径约为3nm.CdSe-脂质体复合体的平均尺寸大约20nm,TEM清楚地显示了CdSe量子点被诱捕在脂质体中.荧光Mapping显示了CdSe-脂质体复合体的发光强度分布.脂质体方法转移TOPO包覆的CdSe量子点,借助了磷脂的双分子链与CdSe表面的TOPO配体之间的疏水相互作用,在CdSe的第一配体层外部形成第二配体层,保留了CdSe的存在环境,光致发光光谱表明,量子点-脂质复合体基本保持了CdSe核量子点的发射效率.     

脂质体中不同种类羧酸钾对草酸钙晶体生长的调控作用

首次研究了狼磷脂-水脂质体中不同种类羧酯钾对草酸钙晶体生长的调控作用 。加入一元DAc只诱导一水草酸钙（COM）生成。二元K_2tart在其浓度大于1. 0mmol/L时可以诱导三水草酸钙（COT）生成。而加入三元的K_3cit和四元的 K_2edta后， 在不同的浓度下，可以分别诱导COM，二水草酸钙（COD）和COT的生 成。在低浓度（—3.3-17mmol/L）范围，， COD含量达到100%；而在较高浓度(＞ 17mmol/L)时，COD减少，COT含量增加。在不同的浓度区间，无论是COM含量减少， 还是COT含量增加，或者是COD含量的先增加后减少，均与该羧酸钾浓度的对数呈线 性关系。不同羧酯钾抑制COM生长并诱导COD形成的能力顺序为：K_3cit＞K_2edta ＞＞K_2tart-KAC,诱导COT生长的能力顺序为：K_2tart＞＞K_3cit＞K_2edta＞＞ KAc.由此推测抑制草酸钙结石形成的潜在效率依次为：K_3cit＞K_2edta＞＞ K_2tart＞＞KAc.