1
|
Eckhardt D, Semeraro EF, Steigenberger J, Schnur J, Kalie L, Massing U, Pabst G, Heerklotz H. Eutectic Resolves Lysolipid Paradox in Thermoresponsive Liposomes. Mol Pharm 2024; 21:1768-1776. [PMID: 38381374 DOI: 10.1021/acs.molpharmaceut.3c01094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
A better molecular understanding of the temperature-triggered drug release from lysolipid-based thermosensitive liposomes (LTSLs) is needed to overcome the recent setbacks in developing this important drug delivery system. Enhanced drug release was previously rationalized in terms of detergent-like effects of the lysolipid monostearyl lysophosphatidylcholine (MSPC), stabilizing local membrane defects upon LTSL lipid melting. This is highly surprising and here referred to as the 'lysolipid paradox,' because detergents usually induce the opposite effect─they cause leakage upon freezing, not melting. Here, we aim at better answers to (i) why lysolipid does not compromise drug retention upon storage of LTSLs in the gel phase, (ii) how lysolipids can enhance drug release from LTSLs upon lipid melting, and (iii) why LTSLs typically anneal after some time so that not all drug gets released. To this end, we studied the phase transitions of mixtures of dipalmitoylphosphatidylcholine (DPPC) and MSPC by a combination of differential scanning and pressure perturbation calorimetry and identified the phase structures with small- and wide-angle X-ray scattering (SAXS and WAXS). The key result is that LTSLs, which contain the standard amount of 10 mol % MSPC, are at a eutectic point when they release their cargo upon melting at about 41 °C. The eutectic present below 41 °C consists of a MSPC-depleted gel phase as well as small domains of a hydrocarbon chain interdigitated gel phase containing some 30 mol % MSPC. In these interdigitated domains, the lysolipid is stored safely without compromising membrane integrity. At the eutectic temperature, both the MSPC-depleted bilayer and interdigitated MSPC-rich domains melt at once to fluid bilayers, respectively. Intact, fluid membranes tolerate much less MSPC than interdigitated domains─where the latter have melted, the high local MSPC content causes transient pores. These pores allow for fast drug release. However, these pores disappear, and the membrane seals again as the MSPC distributes more evenly over the membrane so that its local concentration decreases below the pore-stabilizing threshold. We provide a pseudobinary phase diagram of the DPPC-MSPC system and structural and volumetric data for the interdigitated phase.
Collapse
Affiliation(s)
- Daniel Eckhardt
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg D79104, Germany
| | - Enrico F Semeraro
- Biophysics, Institute of Molecular Bioscience (IMB), NAWI Graz, University of Graz, Graz 8010, Austria
- Field of Excellence BioHealth, University of Graz, Graz 8010, Austria
| | - Jessica Steigenberger
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg D79104, Germany
| | - Johannes Schnur
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg D79104, Germany
| | - Louma Kalie
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg D79104, Germany
| | - Ulrich Massing
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg D79104, Germany
| | - Georg Pabst
- Biophysics, Institute of Molecular Bioscience (IMB), NAWI Graz, University of Graz, Graz 8010, Austria
- Field of Excellence BioHealth, University of Graz, Graz 8010, Austria
| | - Heiko Heerklotz
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg D79104, Germany
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
- BIOSS Signaling Research Center, Freiburg D79104, Germany
| |
Collapse
|
2
|
Bi YZ, Luo YL, Luo RM, Ji C, Gao S, Bai S, Wang YR, Dong FJ, Hu XL, Guo JJ. High freezing rate improves flavor fidelity effect of hand grab mutton after short-term frozen storage. Front Nutr 2022; 9:959824. [PMID: 35958244 PMCID: PMC9361012 DOI: 10.3389/fnut.2022.959824] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 07/01/2022] [Indexed: 11/26/2022] Open
Abstract
Taking the eutectic point as the final freezing temperature, the differences of flavor substances of in hand grab mutton (HGM) frozen at three rates of 0. 26 cm/h (−18°C), 0.56 cm/h (−40°C) and 2.00 cm/h (−80°C) were determined and analyzed. The results showed that the flavor of HGM decreased significantly after freezing. With the increase of freezing rate, the contents of aldehydes, alcohols, ketones, acids, esters, others, free amino acids and 5′-nucleotides were higher, and the content of specific substances was also generally increased. All samples from unfrozen and frozen HGM could be divided into four groups using an electronic nose based on different flavor characteristics. Seven common key aroma components were determined by relative odor activity value (ROAV), including hexanal, heptanal, octanal, nonanal, (E)-oct-2-enal, (2E,4E)-deca-2,4-dienal and oct-1-en-3-ol. The higher the freezing rate, the greater the ROAVs. Taste activity values calculated by all taste substances were far <1, and the direct contribution of the substances to the taste of HGM was not significant. The equivalent umami concentration of HGM frozen at −80°C was the highest. These findings indicated that higher freezing rate was more conducive to the retention of flavor substances in HGM, and the flavor fidelity effect of freezing at −80°C was particularly remarkable.
Collapse
Affiliation(s)
- Yong-Zhao Bi
- School of Food & Wine, Ningxia University, Yinchuan, China.,National R & D Center for Mutton Processing, Yinchuan, China
| | - Yu-Long Luo
- School of Food & Wine, Ningxia University, Yinchuan, China.,National R & D Center for Mutton Processing, Yinchuan, China
| | - Rui-Ming Luo
- School of Food & Wine, Ningxia University, Yinchuan, China.,National R & D Center for Mutton Processing, Yinchuan, China
| | - Chen Ji
- National R & D Center for Mutton Processing, Yinchuan, China.,School of Agriculture, Ningxia University, Yinchuan, China
| | - Shuang Gao
- National R & D Center for Mutton Processing, Yinchuan, China.,School of Agriculture, Ningxia University, Yinchuan, China
| | - Shuang Bai
- National R & D Center for Mutton Processing, Yinchuan, China.,School of Agriculture, Ningxia University, Yinchuan, China
| | - Yong-Rui Wang
- National R & D Center for Mutton Processing, Yinchuan, China.,School of Agriculture, Ningxia University, Yinchuan, China
| | - Fu-Jia Dong
- School of Food & Wine, Ningxia University, Yinchuan, China.,National R & D Center for Mutton Processing, Yinchuan, China
| | - Xiao-Lei Hu
- School of Food & Wine, Ningxia University, Yinchuan, China.,National R & D Center for Mutton Processing, Yinchuan, China
| | - Jia-Jun Guo
- School of Food & Wine, Ningxia University, Yinchuan, China
| |
Collapse
|
3
|
Kim HG, Lee J, Makov G. Phase Diagram of Binary Alloy Nanoparticles under High Pressure. Materials (Basel) 2021; 14:ma14112929. [PMID: 34072298 PMCID: PMC8199147 DOI: 10.3390/ma14112929] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/23/2021] [Accepted: 05/24/2021] [Indexed: 11/16/2022]
Abstract
CALPHAD (CALculation of PHAse Diagram) is a useful tool to construct phase diagrams of various materials under different thermodynamic conditions. Researchers have extended the use of the CALPHAD method to nanophase diagrams and pressure phase diagrams. In this study, the phase diagram of an arbitrary A–B nanoparticle system under pressure was investigated. The effects of the interaction parameter and excess volume were investigated with increasing pressure. The eutectic temperature was found to decrease in most cases, except when the interaction parameter in the liquid was zero and that in the solid was positive, while the excess volume parameter of the liquid was positive. Under these conditions, the eutectic temperature increased with increasing pressure.
Collapse
Affiliation(s)
- Han Gyeol Kim
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Korea;
| | - Joonho Lee
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Korea;
- Correspondence: (J.L.); (G.M.)
| | - Guy Makov
- Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
- Correspondence: (J.L.); (G.M.)
| |
Collapse
|