Papers by Keyword: Liposome

Abstract: The total phenolic content and antioxidant activities of five edible mushrooms (Pleurotus djamor, Agaricus bisporus, Hericlum erinaceus, Coprinus atramentraris and P. ostreatus) were evaluated. The Coprinus atramentraris ethanolic extract (CE) showed the promising antioxidant property and had a strong relationship with phenolic compound content. Liposome-containing CE formulations, were prepared with various lipid composition. The liposome formulation, L1, which composed of phospholipids and cholesterol at ratio of 6:4 gave the highest entrapment efficiency (24.03%), small particle size (143.03 nm) and favorable particle size distribution (0.311) with small values of zeta potential (-30.2 mV). L1 showed good anti-elastase property (IC50 0.029) and no cytotoxicity effect to the human skin fibroblasts and melanoma cells even at the highest concentration of 1 mg/mL compared to the unformulated extract. The in vitro skin permeation studies, using human cadaver skin and modified Franz-diffusion cells, showed that the L1 was able to considerably increase the rate of permeation of phenolic compounds in L1 compared to the CE solution. These results reflect the use of L1 as active agents in cosmeceuticals.

Abstract: The present study focuses on characterization the physical properties of liposome formulation which was dispersed in HPMC matrix and lyophilized in the presence of disaccharides. The lyophilized formulations featured cationic dimethyldioctadecylammonium (DDA) to produce dry solid and overcome limitations in terms of detrimental phase separation in phospholipid membranes during production process. Disaccharides, such as sucrose and lactose, have been reported to protect phospholipid membranes during drying, while HPMC was used as dispersed matrix to inhibit recrystallization of disaccharide. Their physical properties were characterized including their morphology using scanning electron microscopy (SEM), crystallinity using x-ray diffractometry (XRD), and solid phase separation using differential scanning calorimetry (DSC). On the basis of these evaluations it was found that the presence of sucrose and HPMC in the formulation showed a miscible mixture and relatively less crystalline-forming properties compared to those using lactose, thus potentially construct a stable dried liposomal formulation. The present study reveals prospective advantages of using combination of sucrose and HPMC in development of dried–DDA liposomal formulation.

Abstract: This study aimed at investigating positive and negative potential effect on phospholipid lubrication for artificial joint. Surface potentials of CoCrMo in saline were measured once per day for 1 week to simulate corrosion of implanted artificial joint. Both +250 mV and-250 mV were applied on CoCrMo. 2mg/ml DPPC liposome was fabricated to produce lipidic adsorption on CoCrMo. Friction tests were carried out on cartilage vs. CoCrMo and UHMWPE vs. CoCrMo. The results showed that superficial potential of CoCrMo in saline changed from-177 mV at 1^st day to 133mV at 7^th day. Lubrication performance of DPPC liposome without potential was declined gradually. Liposome@-250 mV sustained low friction coefficient of both tribopairs whereas liposome@+250 mV greatly increased friction coefficient of UHMWPE vs. CoCrMo from 0.041 to 0.076. It demonstrated that negative potential enhanced adsorption of DPPC liposome, and promoted its lubrication. In contrast, positive potential on CoCrMo due to corrosion deteriorated liposome lubrication.

Abstract: This study aimed to optimize liposome-mediatedtransfection conditions of pEGFP-N1 in FRT cells and to investigatewhether the optimized conditions were the optimal liposome-mediated transfectionconditions of the other vectors in FRT cells or not. The pEGFP-N1 were transfectedinto FRT cells, with the conditions of different cell confluence、ratio and quantity of vectors / liposome. At the sametime, pEGFP-N1-Aquaporin1、pEGFP-N1-Aquaporin3and pEGFP-N1-Aquaporin4 were transfected into FRT cells, respectively, withconditions of being same as pEGFP-N1. The inverted fluorescent microscopy was used to observe cytotoxicity and the expressionof EGFP in FRT cells. Transfection efficiency was measured by flow cytometry and cell viability was measured by trypanblue exclusion. The results showed that the expression of EGFP reachedthe highest at 36h after transfection. Flow cytometryand trypan blue exclusion tests showed when the cell confluence was 70%、the ratio and quantity of vectors / liposome was 1: 4(2.0ng: 8.0μL), pEGFP-N1 got higher transfection efficiency (46.97±0.32) % andcell viability (63.47±0.32) %. Under the same conditions, AQP1、AQP3 and AQP4 got the highest transfection efficiency and higher cell viability, too. The study would provide anexperimental evidence for efficient transfection of the other vectors in FRT cells.

Abstract: Investigations were carried out to optimize ultrasonic-assisted preparation of liposome-encapsulated paprika red. The effect of process variables namely the ratio of soybean lecithin to paprika red, solvent volume, cholesterol content and sonication time was evaluated using single-factor test and response surface method (RSM). The liposomes showed significant effect on the improvement of light irradiation stability of paprika red, and the stability was greatly improved when antioxidants such as tert-butyl hydroquinone (TBHQ) or dl-α-tocopherol were introduced. The optimal ingredient for liposome-incorporated paprika red was 0.1% dl-α-tocopherol supplemented, in which 32.3% paprika red remained from degradation after light irradiation for 9 h with the intensity of 4000 lux, comparing with 0% that of the control.

Abstract: Monitoring of the organophosphorus pesticides dichlorvos at very low levels has been achieved with liposome-based nanobiosensors. The enzyme acetylcholinesterase was effectively stabilized within the internal nanoenvironment of the liposomes. Within the liposomes, the pH sensitive fluorescent indicator pyranine was also immobilized for the optical transduction of the enzymatic activity. Increasing amounts of pesticides lead to the decrease of the enzymatic activity for the hydrolysis of the acetylcholine and thus to a decrease in the fluorescent signal of the pH indicator. The decrease of the liposome biosensors signal is relative to the concentration of dichlorvos down to 10^-12 M levels. Also a colorimetric screening device for pesticide analysis has been evaluated.

Abstract: Supercritical reverse phase evaporation (SRPE) is a new technique for preparation liposomes with supercritical fluid instead of organic solvent. The process has characteristic for simple and a high coating ratio for water-soluble substances. In this paper, the technique was used to synthesize metronidazole liposomes and the effects of the process parameters on the particle size and the coating ratio of liposomes were investigated in detail. The liposomes with a volume average diameter of 190-350nm were successfully prepared by this technique and the coating ratio for metronidazole liposomes was as high as 48.2%. It was confirmed that the temperature, pressure and equilibrium time had great effects on the particle size and the coating ratio.As the temperature, pressure increased and the solution pH increased from 1 to 7, the particle size increased to a maximum and then gradually decreased, while the coating ratio increased to the maximum and then showed a significant downward trend, indicating that the rate of metronidazole liposomes coated was more susceptible to the influence of the experimental parameters

Abstract: Objective To optimize the preparation technology of salicylic acid liposome gel. Method Salicylic acid liposome was prepared with reverse evaporating method, and liposome gel was prepared using carbomer-940 as matrix. The encapsulation efficiency and leaking percentage of salicylic acid liposome was determined with centrifugal method, and the preparation technology of liposome gel was optimized with orthogonal test. Results The encapsulation efficiency of salicylic acid liposome was 75.86％, leaking percentage was 1.37％. The optimal preparation technology of liposome gel were carbomer 3g, glycerol 15g, mixing temperature 40°C, mixing time 15min. Conclusion Reverse evaporating method was a good method to prepare salicylic acid liposome with higher encapsulation efficiency and better stability. The optimized preparation process of liposome gel was desirable, and the characteristics of product was stable and uniform.

Abstract: Liposome has proven a promising carrier for its special structure and characterization, and can be widely used in pharmacy and cosmetics. Supercritical reverse phase evaporation (SRPE) is a new technique for preparation liposomes with supercritical fluid instead of organic solvent. It features that the preparation process is simple and a high coating ratio is obtained for water-soluble substances. In this paper, the technique was used to synthesize liposomes with water soluble glucose and the effects of the processing technologies parameters on the particle size and the coating ratio of liposomes which were investigated in detail. The liposomes with a volume average diameter of 290-330nm were successfully prepared by this technique and the coating ratio for water-soluble glucose was as high as 27.3%, while it was only 12.5% by the process of physical dispersant in water. It was confirmed that the temperature, pressure and equilibrium time had great effects on the particle size and the coating ratio. As the temperature increased from 35°C to 65°C, the particle size decreased obviously to its minimum value and then changed begins to increase . With the pressure increased from 10MPa to 30MPa, the particle size first decreased and then kept approximately constant. As the equilibrium time increased from 15min to 45min, the particle size first kept an approximately constant value and then increased greatly. Increasing either the temperature from 35°C to 65°C or the pressure from 10MPa to 20MPa, the coating ratio increased remarkably, but it decreased as the pressure increased from 20MPa to 25MPa.

Abstract: In the present study, methylated N-(4-N,N-dimethylaminocinnamyl) chitosan (TM65CM50CS) was synthesized and investigated for oral protein drug delivery by combining with liposomes entrapped bovine serum albumin (FITC-BSA), a model protein. FITC-BSA liposomes composed of egg yolk phosphatidylcholine and sodium oleate in molar ratio of 10:2 were prepared by thin film hydration method. The TM65CM50CS coated liposomal FITC-BSA was evaluated for transport of protein and its cytotoxicity in Caco-2 cells. Moreover, the in vitro stability of BSA in TM65CM50CS coated liposomes was also examined by the degradation of protein from pancreatin. The mean particle size and zeta-potential of liposomes were 101+0.02 nm and -27.44+2.02 mV, respectively. Initial FITC-BSA (2.5% w/w) to lipid showed the highest percentage entrapment efficiency (50.13%) and FITC-BSA content (8.08 mg/g of lipid). The results of FITC-BSA transport showed that TM65CM50CS coated FITC-BSA liposomes enhanced protein permeability across Caco-2 cell monolayers with low cytotoxicity. In addition, these liposomes could protect the degradation of protein from pancreatin. Our studies demonstrated that TM65CM50CS coated liposomes have the potential to be used as an oral protein drug delivery.