Most temperature sensitive liposomes take advantage of the inherent increase in permeability associated with the acylchain melting phase transition 2630. Liposomes, sphereshaped vesicles consisting of one or more phospholipid bilayers, were first described in the mid60s. Phase transition temperature of phospholipids and lipid bilayers depends on the following. The transition range would occur over ic or less, in other words it would be as sharp as the. The liposomes under less osmotic pressure formed a softer layer compared to the 33% naclfilled liposomes. As the data show in the case of liposomes in k 2 s o 4, kc1, and kno 3 solutions the sign at electrophoretic mobility reverses concurrently with the lipid phase transition. Effects of urea and trimethylaminenoxide on fluidity of liposomes.
These liposomes typically exhibited minimal drug release at or below physiological temperatures but released their encapsulated contents upon increasing the temperature to the gel l hv liquidcrystalline l a phase transition temperature t c over a period of approximately 30 min 1. A liposome is a vesicle composed of phospholipids with a structure similar to the biological membrane. Cell membranes, however, also contain embedded proteins and other lipids. Transition temperature an overview sciencedirect topics. Liposomes have a characteristic t c transition temperature, at which they transit from gel phase to liquid crystalline phase.
Temperature sensitive liposomes release encapsulated drugs at the melting phase transition temperature t m of the lipid bilayer figure 16. For liposomes formed from pure phosphatidylcholine pc, see fig. The effects of lyophilization on the physicochemical. Thermodynamic properties of the lipid bilayer transition. This occurs at a temperature known as the transition temperature. Temperaturetriggered nanotechnology for chemotherapy. Nikpoor, solmaz ghaffari, hossein attar, mohammad mashreghi and mahmoud r. Aerosolization of low phase transition temperature. Curves of the temperature dependence of elec trophoretic mobility of liposomes in the presence of different concentrations of trinitrophenol t n p h are shown in fig. Concentrations of lipids are expressed as molar ratios of phospholipids. Effect of gentamicin on the transition temperature and permeability to glycerol of phosphatidylinositolconfining liposomes received 3 m arch 1986. The encapsulation efficiency, initial size, and drug retention of the vesicles were tested over a 48hr period employing radiolabeled inulin as a model drug. Because of this, liposomes have been widely applied in.
The depc liposomes transition temperature tm 12c werecooledfrom20c to 0cat a rate of0. A new temperaturesensitive liposome for use with mild. Drug content in the liposome dispersion and unentrapped drug were analyzed with rphplc system beckman, usa. It is shown that the fullereneexchange reaction from the cyclodextrin cavity to liposomes, to prepare lipid membraneincorporating fullerenes, occurred above the phase transition temperature tm of liposomes. Novel temperaturesensitive liposomes with prolonged. A rapid and highly sensitive biomarker detection platform. After addition of the hydrating medium, the lipid suspension should be maintained above the tc.
The stability of dopepeglipid liposomes, prepared at high ph, against a. For high transition lipids, this is easily accomplished by transferring the lipid suspension to a round bottom flask and placing the flask on a rotory evaporation system without a vacuum. Hydratedsingle component phospholipid bilayers can be in a liquidcrystalline fluid state or in a gel state. Influence of lipid composition on the phase transition. Liposome permeability and phase transition willamette university. Phase transition temperatures for glycerophospholipids. When liposomes are heated to their transition temperature, both gel and. Eradication of mucoid pseudomonas aeruginosa in an animal model of chronic pulmonary infection has been previously demonstrated following the intratracheal administration of fluidosomes, a low phase transition temperature low tc liposomal tobramycin preparation administered in liquid form beaulac et al.
The release of entrapped dox from liposomes at various temperatures between 30c and 45c and time points between 0 and 3600 s was determined by measuring the amount of entrapped dox that was released from a given sample of liposomes as a function of time at a given temperature. Temperature induced release of dox from liposomes in vitro. The effect of phase transition temperature on therapeutic efficacy of liposomal bortezomib volume. Physical and biological properties of cationic triesters of. Indeed, it could provide an additional means for tuning the chainmelting transition temperature to the nearphysiological range. Liposomes in gel phase are immobilized onto silicon dioxide sensors and the sensor cell temperature is increased until passing the tm of the lipid. Nanotechnology research center, pharmaceutical technology institute, mashhad university of medical sciences, mashhad. Shifts in chainmelting transition temperature of liposomal.
C the lipid structure in the liquid crystalline state, ie temperature above the transition temperature. Oct 22, 2020 when the liposomes are heated close to the phase transition temperature, the line tension drastically decreases and then vanishes according to the following law. Aug 07, 2003 the size of the shifts in chainmelting transition that are induced by admixture of peglipids is such that this must be taken into account in the formulation of temperature sensitive liposomes. Sep 04, 2015 photothermally triggered lipid bilayer phase transition and drug release from gold nanorod and indocyanine green encapsulated liposomes. At 24 h after injection, average values of tumor uptake higher than 10%. Of all the liposomes tested, the greatest encapsulation efficiency was found for the dspc liposomes 2. Mppc 10% formulation, and at 37c for 20 minutes for the dppc. Studies have shown that when the ambient temperature is above a phase transition temperature t m, the liposome membrane transforms from a solidlike gel phase to a liquidcrystalline phase 23. Evaluation of phase transition temperature of liposomes by using the. With a given polar head, the transition temperature depends on the type and length of the acyl chains the longer the chain, the higher the temperature. Pure dppc bilayers exhibit characteristic transitions with low enthalpy changes and a sharp main transition tm, both of which occur at the expected transition temperatures of 35. Trigger release liposomes such as temperature sensitive liposomes or radiation sensitive liposomes should be engineered in a way to have phase separated domains.
To have a higher phase transition temperature than small unilamellar dppc vesicles, paasonen et al. Pdf effect of lipid phase transition on the binding of. Phase transitions in phospholipid bilayers iubmb journal wiley. The lcsts of pnipaamcodmapaam and pnipaamcodmaam were observed at 41. Aqualitative discussion may be outlined as follows. The phase transition temperature of the saturated derivatives is very similar to that of the precursor. In this respect, a firstorder phase transition is completely correlated, that is completely cooperative.
Jan 07, 2014 dppc liposomes ranging from 90 nm to 160 nm in diameter were prepared and used for studies of the formation of supported lipid membranes on silica sio2 at temperatures below and above the gel to liquidcrystalline phase transition temperature tm 41 c, and by applying temperature gradients through tm. Differential scanning calorimetry of bilayer membrane phase. It is shown that the fullereneexchange reaction from the cyclodextrin cavity to liposomes, to prepare lipid membraneincorporating fullerenes, occurred above the phase transition temperature tm. Tunable surface properties of temperatureresponsive polymer. The objective of this study was to investigate the influence of molar ratio of 1,2dipalmitoylsnglycero3phosphocholine dppc and hydrogenated soy phosphatidylcholine hspc on the phase transition temperature tm of the liposomes. Today, they are a very useful reproduction, reagent, and tool in various. Liposomes are a good model system for the cell membrane.
In general, each lipid has a gel phase and a liquid phase. Relationship between phase transition temperature and protonation degree of dipalmitoylphosphatidylcholine in lipos omes marta s. Becausefoursamplescan becooledsimultaneously, acontrolwasalwaysrunbesidethe experimental samples. Liposomes formation is possible only if the temperature is above transition temperature. Since their discovery, liposomes have been subject to extensive evolution, in terms of composition, manufacturing and applications, which led to several openings in both basic and applied life sciences. Lipid thermotropic phase transition database lipidat nist standard reference database 34 avanti polar lipids 700 industrial park drive alabaster, alabama 350079105 205 6632494 800 2270651 contact us. Nearinfrared imageguided delivery and controlled release.
The liposomes exhibited a high content of paclitaxel, which was incorporated within the segregated microdomains coexisting on phospholipid bilayer of. The crystalline transition temperature geltoliquid for phosphatidylcholine from egg is 15 c for the heating curve and 7 c for the cooling curve. Also volatile solvents such as chloroform which are used will tend to evaporate from the container. Changes in temperature can then lead to temperature induced transitions between different types of lamellar phase, or to further lyotropic phases, such as inverted hexagonal or bicontinuous cubic phases7. Liposome preparation avanti polar lipids sigmaaldrich. Liposomes have been widely used as model membranes and in drug.
A liposome formulation for paclitaxel was developed in this study. Temperature and rigiditymediated rapid transport of. Pdf determination of the main phase transition temperature of. Preparation and evaluation of temperature sensitive liposomes. Unsaturated lipids have a significantly lower transition temperature compare to saturated lipids. Destabilization of phosphatidylethanolamine liposomes at the. The sw sample was taken from the supernatant after ultracentrifugation to eliminate any large vesicles. The temperature responsive liposomes remain intact at 37 c and exhibit a sitespeci. Phase behavior and aggregate structure in mixtures of. All these probes, independent of their localization in the liposomes, report a monotonous change in the.
To get a better understanding of the connection between the t m. The phase transition temperature is defined as the temperature required to induce a change in the lipid physical state from the ordered gel phase, where the hydrocarbon chains are fully extended and closely packed, to the disordered liquid crystalline phase, where the hydrocarbon chains are randomly oriented and fluid. Whats is the effect of transition temperature of a lipid in. Small glass test tubes were filled with hepes buffer at room temperature and 5 l of dox loaded liposomes were. Apr 05, 2021 liposomes, sphereshaped vesicles consisting of one or more phospholipid bilayers, were first described in the mid60s. Effect of phase transition temperature of liposomes on. Liposomes are produced when the phospholipid bilayer forms around an aqueous cavity.
What is the effect of the phase transition temperature of the. Detection of phase transition in photosensitive liposomes by. Pure dppc liposomes, pure dppg liposomes, and this mixture all have the same transition temperature. Effect of phase transition temperature of liposomes on preparation of fullereneencapsulated liposomes by the fullereneexchange reaction a. Spinning the round bottom flask in the warm water bath maintained at a temperature above the tc of the lipid suspension allows the lipid to hydrate in its. Evaluation of phase transition temperature of liposomes by.
This occurs at a temperature known as the transition temperature tc. The encapsulated rugs are release at crystalline phase 4. Resuspended lipid dispersion will contain multilamellar liposomes, which can be broken down by repeated freeze thawing in liquid nitrogen 68 times. Phase transitions of lipids and liposomes mettler toledo. Lipid phase transition probed by diode laser light scattering. The phase transition temperature of liposomes, which depends on the tc of the constituent lipids, was an important factor in liposome stability. These lipids have wellspaced lamellarhexagonal phase transition temperatures 12. Estimated mass of liposome layers obtained by modeling of the qcmd results obtained for liposomes adsorbed to silica at 22 oc.
Effects of temperature, acyl chain length, and flowrate. Which phase features tighter packing and lower permeability. In addition, it has been shown that the temperature, at which labelled compounds were released from dppc liposomes, was lower than the t m of dppc 22. By increasing the temperature, the gel state bilayer melts and is converted into the liquid state. Phase transition temperature tc of tsl was dependent on the lipid. Effect of liposome composition and other factors on the. Reconstitution of membrane proteins aston university.
The transition temperature is the temperature at which the lipid phase transitions from a gel to the liquidcrystalline phase. The effect of different lipid components on the in vitro. Effect of polymer phase transition behavior on temperature. Preparation of liposomes mlvs were made by hydrating lipid powder in the appropriate solution at a temperature of at least 108c above its phase transition temperature for 1 h with intermittent vortexing. The drug release could be triggered by the phase transition of cf127 on the surface of the liposome. Soluteinduced shift of phase transition temperature in di. Formulation and pharmacokinetics of thermosensitive. A liposomal formulation able to incorporate a high content of.
Therefore, the percentage of cholesterol used for the preparation of liposomes also affects the ultimate phase transition temperature of the bilayer. Determination of the main phase transition temperature of. Dppgog facilitates temperature triggered drug release from these liposomes diameter, 175 nm and leads to a substantially prolonged plasma halflife for the encapsulated drug with t12 9. Liposome made from pure phospholipids in the absence of cholesterol will not form at temperatures below the phase transition temperature of phospholipid. The effect of phase transition temperature on therapeutic. Stimulusresponsive liposomes as smart nanoplatforms for. An example of this type of temperature responsive liposomes loaded with doxorubicin, thermodox, reached phase iii.
Liposomes in gel phase are immobilized onto silicon dioxide sensors and the sensor cell temperature is increased until passing the tm of the. The liposomes, composed of naturally unsaturated and hydrogenated phosphatidylcholines, with significant phase transition temperature difference, were prepared and characterized. Pdf effect of phase transition temperature of phospholipid on the. Phase transition of the lipid membrane is one of the most important properties of liposomes. In other words, in firstorder transitions there is an abrupt change in the properties of the system at the phase transition temperature. Detection of phase transition in photosensitive liposomes. Electronic supplementary information supporting information. Whats is the effect of transition temperature of a lipid. The compressibility of the membranehas a sharp peak near the transition temperature as shown in fig. The phase transition behavior of the prepared polymers was established from the temperature dependent transmittance change of the solution. Since dppc has a phase transition temperature of 41 c, a 60 c water. Relationship between phase transition temperature and. Pdf effect of gentamicin on the transition temperature. Effects of flavonol glycosides on liposome stability.
What is the effect of the phase transition temperature of. The liposomes are suspended in hepes buffer 10 im hepes, 9 mm nac1, 6 mm kc1, ph 7. When the aqueous solution was heated up, the cf127. Temperature and rigiditymediated rapid transport of lipid.
Handling of liposomes the lipids used in the preparation of liposomes are unsaturated and hence susceptible to oxidation. Nov 12, 2018 liposomes are currently part of the most reputed carriers for various molecular species, from small and simple to large and complex molecules. L aphosphatidylcholine p3556 product information sheet. Which is more motionally free and is a better biological membrane model. The leakage from these liposomes rapidly increases. Wang and kim modified the block copolymer pluronic f127 by attaching cinnamoyl groups cf127 and immobilized it on the surface of epc liposomes resulting in triggered release of its watersoluble payload in response to a temperature change.
If you are viewing this page on a mobile device or would like to print this information for offline use, we have formatted the data into an easy to read pdf. Pdf we investigated the effect of the phase transition temperature t of phospholipid in liposomes on the stability of incorporated retinol. The phase transition may be induced by increasing the temperature above the. Pdf disc formation in cholesterolfree liposomes during.
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