多糖染料木素复合多糖脂质体的制备及其抗前列腺癌机制的研究

目的:通过制备多糖染料木素复合多糖（genistein combined polysaccharide，GCP）脂质体，分别从体内和体外实验评估GCP脂质体用于治疗前列腺癌潜在应用价值，促进纳米技术在前列腺癌化疗中的应用。方法:采用乙醇注入法制备GCP脂质体。通过细胞增殖检测和细胞周期分析技术以及建立前列腺癌荷瘤动物模型等，从体外和体内验证GCP脂质体抗肿瘤效果。结果:GCP脂质体增强了GCP对雄激素敏感的LNCaP细胞增殖的抑制作用，增强了GCP诱导雄激素敏感的LNCaP细胞的凋亡作用。同时，GCP脂质体增强了GCP对肿瘤小鼠肿瘤生长的抑制作用。结论:GCP脂质体相较于GCP，对雄性激素敏感的人类前列腺癌细胞有更好的抗肿瘤效果。     

Impact of Liposomal Drug Formulations on the RBCs Shape,Transmembrane Potential,and Mechanical Properties

Liposomal technologies are used in order to improve the effectiveness of current therapies or to reduce their negative side effects. However, the liposome–erythrocyte interaction during the intravenous administration of liposomal drug formulations may result in changes within the red blood cells (RBCs). In this study, it was shown that phosphatidylcholine-composed liposomal formulations of Photolon, used as a drug model, significantly influences the transmembrane potential, stiffness, as well as the shape of RBCs. These changes caused decreasing the number of stomatocytes and irregular shapes proportion within the cells exposed to liposomes. Thus, the reduction of anisocytosis was observed. Therefore, some nanodrugs in phosphatidylcholine liposomal formulation may have a beneficial effect on the survival time of erythrocytes.     

Whey Protein Isolate Coated Liposomes as Novel Carrier Systems for Astaxanthin

In this work, whey protein isolate (WPI)‐coated astaxanthin‐loaded liposomes are prepared by combining the fabrication of liposomes with the layer self‐assembly deposition technique. The physical properties of such composite carriers are evaluated by zeta potential, particle size, distribution, encapsulation efficiency, and morphology. WPI‐ coated astaxanthin‐loaded liposomes display homodisperse distribution and high encapsulation efficiency with a WPI coating layer surrounding the surface of conventional liposomes by the electrostatic interaction. Fourier transform infrared spectroscopy and X‐ray diffraction analysis reveal that WPI interacts with the lipid bilayer via hydrophobic forces and hydrogen bonding, which result in the successful coating. Based on experimental results of differential scanning calorimetry and thermogravimetric analysis, it is demonstrated that thermal stability of astaxanthin‐loaded liposomes benefits from the formation of surface modification of the WPI‐layer. In addition, the physical stability of WPI‐coated astaxanthin‐loaded liposomes under heating and light is significantly improved as compared with uncoated liposomes. This research might provide scientific guidance for the development of WPI‐coated liposomes as efficient carrier systems for bioactive substances in food and pharmaceutical industry. Practical Applications: To improve lipid membrane stability and to prevent the leakage of encapsulated astaxanthin, a novel carrier system based on WPI coated on the surface of liposomes is prepared through the layer self‐assembly deposition technique. This research suggests that WPI‐coated liposomes represent an effective and stable delivery system for astaxanthin. WPI‐coated liposomes could be developed as efficient carrier systems for bioactive compounds in the food and pharmaceutical industries.     

Accelerated ripening of cheese using liposome-encapsulated enzyme

Improved efficiency of liposome encapsulation of a cheese-ripening enzyme and increased retention of encapsulated enzyme by cheese curd are reported. The economy of enzyme usage for accelerating the rate of ripening of Cheddar cheese has been improved about 100-fold over previously reported methods. This has made feasible the use of microencapsulated enzymes for large-scale cheese production. Objective measurement of cheese ripening by proteolytic indices, and subjective evaluation of flavour quality and intensity by trained taste panels, indicate that cheeses are ripened by the microencapsulated enzyme in half the normal time. Investigations aimed at further improving the efficiency and commercial feasibility of the process are reported, and the possibility of using this technology for other aspects of food processing are discussed.     

A-ring oxidation products from γ-irradiation of cholesterol in liposomes

γ-Irradiation of cholesterol in multilamellar vesicles (MLV) at 0–4°C causes oxidation of the A-ring. Two A-ring oxides formed in considerable amounts are cholest-4-en-3-one (10) and cholest-4-ene-3,6-dione (12) in addition to the usual B-ring oxides. Lesser amounts of cholesta-4,6-dien-3-one (11) are also generated. Compounds 10 and 12 were detected and measured in cholesterol irradiated at less than 0.5 kGy in liposomes containing saturated or unsaturated phospholipids. Lesser amounts of 10 and 12, as well as lesser amounts of other cholesterol oxides, were formed when a major constituent of the MLV was dilinoleoylphosphatidylcholine. Autoxidation of cholesterol in MLV also gave rise to small amounts of 10, 11 and 12.     

Multipronged,strategic delivery of paclitaxel-topotecan using engineered liposomes to ovarian cancer

Context: Synergistically active combinations have been used to enhance therapeutic efficacy for ovarian cancer chemotherapy.

Objective: The synergistically active combination of paclitaxel-topotecan (Pac-Top; 20:1, w/w) were loaded into folate-anchored PEGylated liposomes (FPL-Pac-Top) for safe and effective treatment of ovarian cancer.

Materials and methods: Coupling reactions were carried out using carbodiimide chemistry and confirmed by infrared spectral analysis. These liposomes were studied for shape and physical interaction (and integrity), in vitro drug release kinetics, hemolytic toxicity, ex vivo pharmacodynamics in OVCAR-3 cell lines, and pharmacokinetics in ovarian tumor-bearing mice.

Results: The differential scanning calorimeter studies exhibited melting of liposomes (～150?nm) at ～41?°C. The drug(s) release from liposomes followed Fickian diffusion model. The hematological studies revealed insignificant toxicity to blood cells. In vivo studies showed long circulatory behavior (increased AUC_0–t and AUMC_0–t and MRT) and selective accumulation of FPL-Pac-Top in the ovaries. FPL-Pac-Top showed less necrosis and more apoptosis in flow cytometry. Kaplan–Meier survival analysis revealed the doubling of the survival time with FPL-Pac-Top in comparison to Pac-Top solution.

Discussion and conclusion: Potentiated anti-cancer activity of FPL-Pac-Top was attributed to multiple features viz. thermosensitivity, long circulatory nature and targetability. Such approach could be a paradigm chemotherapeutic approach for safe and effective targeting of cancer.     

Bacteria‐Assisted Selective Photothermal Therapy for Precise Tumor Inhibition

Photothermal therapy (PTT) has drawn extensive research attention as a promising approach for tumor treatment. In this study, a bacteria‐assisted strategy relying on the selective reduction of perylene diimide derivative based supramolecular complex (CPPDI) to radical anions (RAs) by Escherichia coli in hypoxic tumors is developed to realize highly precise PTT of tumors. Noninvasive E. coli are first injected intravenously for selectively accumulating and replicating in the tumor due to the hypoxia tropism. Then, CPPDI is loaded in a peptide‐hybrid matrix metalloproteinase‐2 (MMP‐2) responsive liposome (MRL) and injected intravenously. After accumulated and released from MRL in the tumor where MMP‐2 is overexpressed, CPPDI is reduced by E. coli in the hypoxic tumor environment to produce CPPDI RAs (CRAs), which serve as effective photothermal agents for tumor cells thermal ablation under near‐infrared light irradiation. Since E. coli accumulate and grow in tumor sites selectively, this strategy accurately limits the production of CRAs in tumors for highly selective PTT, which will find great potential for precise tumor inhibition.     

Targeted Delivery of CRISPR/Cas9‐Mediated Cancer Gene Therapy via Liposome‐Templated Hydrogel Nanoparticles

Due to its simplicity, versatility, and high efficiency, the clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 technology has emerged as one of the most promising approaches for treatment of a variety of genetic diseases, including human cancers. However, further translation of CRISPR/Cas9 for cancer gene therapy requires development of safe approaches for efficient, highly specific delivery of both Cas9 and single guide RNA to tumors. Here, novel core–shell nanostructure, liposome‐templated hydrogel nanoparticles (LHNPs) that are optimized for efficient codelivery of Cas9 protein and nucleic acids is reported. It is demonstrated that, when coupled with the minicircle DNA technology, LHNPs deliver CRISPR/Cas9 with efficiency greater than commercial agent Lipofectamine 2000 in cell culture and can be engineered for targeted inhibition of genes in tumors, including tumors the brain. When CRISPR/Cas9 targeting a model therapeutic gene, polo‐like kinase 1 (PLK1), is delivered, LHNPs effectively inhibit tumor growth and improve tumor‐bearing mouse survival. The results suggest LHNPs as versatile CRISPR/Cas9‐delivery tool that can be adapted for experimentally studying the biology of cancer as well as for clinically translating cancer gene therapy.