Evaluating the Structure and Dynamics of Water in Nanoemulsions Using Rheology, Light Scattering, and Differential Scanning Calorimetry

Lipophilic substituted zinc(II) phthalocyanines: 2,3,9,10,16,17,23,24-octakis[(N,N-dimethylaminoethylsulfanyl)]phthalocyaninatozinc(II) (S1) and tetrakis(N,N-dibutylaminoethoxy)phthalocyaninatozinc(II) (3) were incorporated into soybean L-α-phosphatidylcholine (SPC) liposomes of 100 nm diameter. Liposomes were characterized by static light scattering (SLS), transmission electronic microscopy (TEM), and differential scanning calorimetry. The fluorescence quantum yield and singlet molecular oxygen production of 3 are Φ F = 0.15 and ΦΔ = 0.24, respectively, whereas the same photophysical parameters for S1 are Φ F = 0.13 and ΦΔ = 0.51. Higher values of Φ F and ΦΔ are obtained in organic solvent for both dyes. Synthesis of compound 3 has also been reported.

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Thermodynamic stability and formation of aggregates of human immunoglobulin G characterised by differential scanning calorimetry and dynamic light scattering

Journal of Biochemical and Biophysical Methods ◽

10.1016/j.jbbm.2005.12.003 ◽

2006 ◽

Vol 66 (1-3) ◽

pp. 73-86 ◽

Cited By ~ 54

Author(s):

Karin Ahrer ◽

Andrea Buchacher ◽

Günter Iberer ◽

Alois Jungbauer

Keyword(s):

Differential Scanning Calorimetry ◽

Light Scattering ◽

Dynamic Light Scattering ◽

Thermodynamic Stability ◽

Immunoglobulin G ◽

Human Immunoglobulin ◽

Scanning Calorimetry ◽

Human Immunoglobulin G

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Effect of Diluents on Interfacial Properties and SAGD Emulsion Stability: II. Differential Scanning Calorimetry and Light Scattering Methods

10.2118/165384-ms ◽

2013 ◽

Cited By ~ 2

Author(s):

Vittoria Balsamo ◽

Jenny Phan ◽

Duy Nguyen

Keyword(s):

Differential Scanning Calorimetry ◽

Light Scattering ◽

Emulsion Stability ◽

Interfacial Properties ◽

Scanning Calorimetry

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Phase transitions of liposomes: When light meets heat

Journal of Physics Condensed Matter ◽

10.1088/1361-648x/ac45b7 ◽

2021 ◽

Author(s):

C S Velez-Saboyá ◽

J R Guzmán-Sepúlveda ◽

Jesus Carlos Ruiz-Suárez

Keyword(s):

Differential Scanning Calorimetry ◽

Phase Transitions ◽

Light Scattering ◽

Dynamic Light Scattering ◽

Membrane Thickness ◽

Scanning Calorimetry ◽

Contraction Process ◽

Exothermic Process ◽

Gel Phase ◽

Derivatives Of

Abstract Phase transitions of liposomes are normally studied by diﬀerential scanning calorimetry (DSC). A suspension of liposomes is subjected to an increase (decrease) of temperature and when heat is absorbed (released), the liposomes transit from a gel (liquid) to a liquid (gel) phase. This endothermic (exothermic) process takes place at a temperature called the melting temperature Tm, which is distinctive of the type of lipids forming the vesicles. The vesicles, though, also modify their size in the transition. Indeed, the thickness of the membranes decreases (increases) because carbon tails misalign (align). Concomitant with the modiﬁcations in the membrane thickness, the diameter (D) of the liposomes changes too. Therefore, when they are inspected by light, the scattered signal carries information from such dilatation (contraction) process. We performed careful experiments using dynamic light scattering (DLS) as a function of temperature to detect the size changes of diﬀerent liposomes. Gaussian ﬁts of the derivatives of the D vs T curves coincide within 1% with thermograms, which hints to the possibility of performing thermodynamic studies of lipid systems employing light.

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