The elution profile of immobilized liposome chromatography: determination of association and dissociation rate constants

Photodynamic inactivation of viruses by immobilized chlorin-containing liposomes

The viral safety of blood derived products relies in properly chosen inactivation procedures. In this way, it has been reported that some photosensitizers are useful products for blood sterilization. The data presented here show the high incorporation efficiency of the chlorin 3-phorbinepropanol, 9,14-diethyl-4,8,13,18-tetramethyl-20-(3S-trans) (CHL) into anionic unilamellar liposomes, give a protocol for the steric immobilization of chlorin-containing liposomes in a chromatographic support and provide the studies of photodynamic inactivation of bovine viral diarrhea virus (BVDV) and encephalomyocarditis virus (EMCV) with chlorin-containing liposomes, free in solution and immobilized on Sephacryl S-1000 beads. The study demonstrates the successful inactivation of the enveloped virus BVDV by both preparations in culture medium and the resistance of the non-enveloped virus EMCV. The effectiveness of CHL-containing liposomes, in solution and immobilized in the chromatographic support, decreased when the culture media was replaced with human blood plasma. Moreover, the reduction factor of the virus titer after irradiation was smallest when immobilized liposomes were used. Nevertheless, the reduction factor for the virus titers of enveloped viruses after irradiation of human blood plasma samples with immobilized chlorin-containing liposomes increased with the reduction of the sample thickness. The more outstanding aspect of this paper is the design of a system useful for blood sterilization that can be easily removed after photodynamic treatment and, therefore, able to be applied in the manufacturing processes.

Screening and identification of permeable components in a combined prescription of Danggui Buxue decoction using a liposome equilibrium dialysis system followed by HPLC and LC-MS

A new method, i.e., liposome equilibrium dialysis followed by HPLC and LC-MS analysis, has been developed for the screening of permeable components in combined prescriptions of Danggui Buxue decoction (CPDBD). Multiple permeable components were simultaneously predicted by comparison of chromatograms of CPDBD extract before and after interaction with liposome membranes. A diode-array detector (DAD) and an evaporative light scattering detector (ELSD) were used, and the permeable compounds were identified by comparison with the available reference compounds and confirmed by on-line LC-MS. About fifteen compounds in a CPDBD extract were found to interact with liposome membranes. They were identified as calycosin-7-O-beta-D-glucoside (1), senkyunolide I or H (2), ononin (3), (6alphaR,11alphaR)-9,10-dimethoxypterocarpan-3-O-beta-D-glucoside (4), (3R)-2'-hydroxy-3',4'-dimethoxyisoflavan-7-O-beta-D-glucoside (5), calycosin (6), astragaloside IV (7), isoastragaloside II (8), formononetin (9), (6alphaR, 11alphaR),-3-hydroxy-9,10-dimethoxypterocarpan (10), (3R)-7,2'-dihydroxy-3',4'-dimethoxyisoflavan (11), astragaloside I (12), isoastragaloside I (13), E-ligustilide (14), and Z-ligustilide (15), respectively. Among all permeable components, 1, 3, 6, and 9 (flavonoids), 2, 14, and 15 (phthalides), and 7 (saponins) have been considered as major bioactive components in CPDBD. Therefore, this new method appears useful as a first step in the screening of bioactive components in natural products including Traditional Chinese Medicines (TCMs).