Filter-extruded liposomes revisited: a study into size distributions and morphologies in relation to lipid-composition and process parameters

Askell Hinna, Frank Steiniger, Stefan Hupfeld, Paul C. Stein, Judith Kuntsche, Martin Brandl

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

Filter-extrusion is a widely used technique for down-sizing of phospholipid vesicles. In order to gain a detailed insight into size and size distributions of filter-extruded vesicles composed of egg phosphatidyl-choline (with varying fractions of cholesterol) – in relation to extrusionparameters (pore-size, number of filter passages, and flow-rate), flow field-flow fractionation in conjunction with multi-angle laser light scattering (AF4-MALLS, Wyatt Technology Corp., Santa Barbara, CA) was employed. Liposome size-distributions determined by AF4-MALLS were compared with those of dynamic light scattering and correlated with cryo-transmission electron microscopy and 31P-NMR-analysis of lamellarity. Both the mean size of liposome and the width of size distribution were found to decrease with sequential extrusion through smaller pore size filters, starting at a size range of &70–415nm upon repeated extrusion through 400nm pore-filters, eventually ending with a size range from &30 to 85nm upon extrusion through 30nm pore size filters. While for small pores sizes (50 nm), increased flow rates resulted in smaller vesicles, no significant influence of flow rate on mean vesicle size was seen with larger pores. Cholesterol at increasing mol fractions up to 0.45 yielded bigger vesicles (at identical process conditions). For a cholesterol mol fraction of 0.5 in combination with small filter pore size, a bimodal size distribution was seen indicating cholesterol micro-crystallites. Finally, a protocol is suggested to prepare large (300 nm) liposomes with rather narrow size distribution, based on the filter extrusion at defined flow-rates in combination with freeze-/ thaw-cycling and bench-top centrifugation.
OriginalsprogEngelsk
TidsskriftJournal of Liposome Research
Vol/bind26
Udgave nummer1
Sider (fra-til)11-20
ISSN0898-2104
DOI
StatusUdgivet - 2016

Fingeraftryk

Lipids
Field Flow Fractionation
Centrifugation
Microscopy
Phospholipids

Citer dette

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title = "Filter-extruded liposomes revisited: a study into size distributions and morphologies in relation to lipid-composition and process parameters",
abstract = "Filter-extrusion is a widely used technique for down-sizing of phospholipid vesicles. In order to gain a detailed insight into size and size distributions of filter-extruded vesicles composed of egg phosphatidyl-choline (with varying fractions of cholesterol) – in relation to extrusionparameters (pore-size, number of filter passages, and flow-rate), flow field-flow fractionation in conjunction with multi-angle laser light scattering (AF4-MALLS, Wyatt Technology Corp., Santa Barbara, CA) was employed. Liposome size-distributions determined by AF4-MALLS were compared with those of dynamic light scattering and correlated with cryo-transmission electron microscopy and 31P-NMR-analysis of lamellarity. Both the mean size of liposome and the width of size distribution were found to decrease with sequential extrusion through smaller pore size filters, starting at a size range of &70–415nm upon repeated extrusion through 400nm pore-filters, eventually ending with a size range from &30 to 85nm upon extrusion through 30nm pore size filters. While for small pores sizes (50 nm), increased flow rates resulted in smaller vesicles, no significant influence of flow rate on mean vesicle size was seen with larger pores. Cholesterol at increasing mol fractions up to 0.45 yielded bigger vesicles (at identical process conditions). For a cholesterol mol fraction of 0.5 in combination with small filter pore size, a bimodal size distribution was seen indicating cholesterol micro-crystallites. Finally, a protocol is suggested to prepare large (300 nm) liposomes with rather narrow size distribution, based on the filter extrusion at defined flow-rates in combination with freeze-/ thaw-cycling and bench-top centrifugation.",
author = "Askell Hinna and Frank Steiniger and Stefan Hupfeld and Stein, {Paul C.} and Judith Kuntsche and Martin Brandl",
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Filter-extruded liposomes revisited : a study into size distributions and morphologies in relation to lipid-composition and process parameters. / Hinna, Askell; Steiniger, Frank; Hupfeld, Stefan; Stein, Paul C.; Kuntsche, Judith; Brandl, Martin.

I: Journal of Liposome Research, Bind 26, Nr. 1, 2016, s. 11-20.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Filter-extruded liposomes revisited

T2 - a study into size distributions and morphologies in relation to lipid-composition and process parameters

AU - Hinna, Askell

AU - Steiniger, Frank

AU - Hupfeld, Stefan

AU - Stein, Paul C.

AU - Kuntsche, Judith

AU - Brandl, Martin

PY - 2016

Y1 - 2016

N2 - Filter-extrusion is a widely used technique for down-sizing of phospholipid vesicles. In order to gain a detailed insight into size and size distributions of filter-extruded vesicles composed of egg phosphatidyl-choline (with varying fractions of cholesterol) – in relation to extrusionparameters (pore-size, number of filter passages, and flow-rate), flow field-flow fractionation in conjunction with multi-angle laser light scattering (AF4-MALLS, Wyatt Technology Corp., Santa Barbara, CA) was employed. Liposome size-distributions determined by AF4-MALLS were compared with those of dynamic light scattering and correlated with cryo-transmission electron microscopy and 31P-NMR-analysis of lamellarity. Both the mean size of liposome and the width of size distribution were found to decrease with sequential extrusion through smaller pore size filters, starting at a size range of &70–415nm upon repeated extrusion through 400nm pore-filters, eventually ending with a size range from &30 to 85nm upon extrusion through 30nm pore size filters. While for small pores sizes (50 nm), increased flow rates resulted in smaller vesicles, no significant influence of flow rate on mean vesicle size was seen with larger pores. Cholesterol at increasing mol fractions up to 0.45 yielded bigger vesicles (at identical process conditions). For a cholesterol mol fraction of 0.5 in combination with small filter pore size, a bimodal size distribution was seen indicating cholesterol micro-crystallites. Finally, a protocol is suggested to prepare large (300 nm) liposomes with rather narrow size distribution, based on the filter extrusion at defined flow-rates in combination with freeze-/ thaw-cycling and bench-top centrifugation.

AB - Filter-extrusion is a widely used technique for down-sizing of phospholipid vesicles. In order to gain a detailed insight into size and size distributions of filter-extruded vesicles composed of egg phosphatidyl-choline (with varying fractions of cholesterol) – in relation to extrusionparameters (pore-size, number of filter passages, and flow-rate), flow field-flow fractionation in conjunction with multi-angle laser light scattering (AF4-MALLS, Wyatt Technology Corp., Santa Barbara, CA) was employed. Liposome size-distributions determined by AF4-MALLS were compared with those of dynamic light scattering and correlated with cryo-transmission electron microscopy and 31P-NMR-analysis of lamellarity. Both the mean size of liposome and the width of size distribution were found to decrease with sequential extrusion through smaller pore size filters, starting at a size range of &70–415nm upon repeated extrusion through 400nm pore-filters, eventually ending with a size range from &30 to 85nm upon extrusion through 30nm pore size filters. While for small pores sizes (50 nm), increased flow rates resulted in smaller vesicles, no significant influence of flow rate on mean vesicle size was seen with larger pores. Cholesterol at increasing mol fractions up to 0.45 yielded bigger vesicles (at identical process conditions). For a cholesterol mol fraction of 0.5 in combination with small filter pore size, a bimodal size distribution was seen indicating cholesterol micro-crystallites. Finally, a protocol is suggested to prepare large (300 nm) liposomes with rather narrow size distribution, based on the filter extrusion at defined flow-rates in combination with freeze-/ thaw-cycling and bench-top centrifugation.

U2 - 10.3109/08982104.2015.1022556

DO - 10.3109/08982104.2015.1022556

M3 - Journal article

C2 - 25826203

VL - 26

SP - 11

EP - 20

JO - Journal of Liposome Research

JF - Journal of Liposome Research

SN - 0898-2104

IS - 1

ER -