TY - JOUR
T1 - Protein antigen adsorption to the DDA/TDB liposomal adjuvant
T2 - effect on protein structure, stability, and liposome physicochemical characteristics
AU - Hamborg, Mette
AU - Jorgensen, Lene
AU - Bojsen, Anders Riber
AU - Christensen, Dennis
AU - Foged, Camilla
PY - 2013/1/1
Y1 - 2013/1/1
N2 - Purpose: Understanding the nature of adjuvant-antigen interactions is important for the future design of efficient and safe subunit vaccines, but remains an analytical challenge. We studied the interactions between three model protein antigens and the clinically tested cationic liposomal adjuvant composed of dimethyldioctadecylammonium (DDA) and trehalose 6,6′-dibehenate (TDB). Methods: The effect of surface adsorption to DDA/TDB liposomes on colloidal stability and protein physical stability/secondary structure was investigated by dynamic light scattering, circular dichroism, Fourier transform infrared spectroscopy and differential scanning calorimetry. Results: Bovine serum albumin and ovalbumin showed strong liposome adsorption, whereas lysozyme did not adsorb. Upon adsorption, bovine serum albumin and ovalbumin reduced the phase transition temperature and narrowed the gel-to-liquid phase transition of the liposomes implying interactions with the lipid bilayer. The protein-to-lipid ratio influenced the liposome colloidal stability to a great extent, resulting in liposome aggregation at intermediate ratios. However, no structural alterations of the model proteins were detected. Conclusions: The antigen-to-lipid ratio is highly decisive for the aggregation behavior of DDA/TDB liposomes and should be taken into account, since it may have an impact on general vaccine stability and influence the choice of analytical approach for studying this system, also/especially at clinically relevant protein-to-lipid ratios. [Figure not available: see fulltext.].
AB - Purpose: Understanding the nature of adjuvant-antigen interactions is important for the future design of efficient and safe subunit vaccines, but remains an analytical challenge. We studied the interactions between three model protein antigens and the clinically tested cationic liposomal adjuvant composed of dimethyldioctadecylammonium (DDA) and trehalose 6,6′-dibehenate (TDB). Methods: The effect of surface adsorption to DDA/TDB liposomes on colloidal stability and protein physical stability/secondary structure was investigated by dynamic light scattering, circular dichroism, Fourier transform infrared spectroscopy and differential scanning calorimetry. Results: Bovine serum albumin and ovalbumin showed strong liposome adsorption, whereas lysozyme did not adsorb. Upon adsorption, bovine serum albumin and ovalbumin reduced the phase transition temperature and narrowed the gel-to-liquid phase transition of the liposomes implying interactions with the lipid bilayer. The protein-to-lipid ratio influenced the liposome colloidal stability to a great extent, resulting in liposome aggregation at intermediate ratios. However, no structural alterations of the model proteins were detected. Conclusions: The antigen-to-lipid ratio is highly decisive for the aggregation behavior of DDA/TDB liposomes and should be taken into account, since it may have an impact on general vaccine stability and influence the choice of analytical approach for studying this system, also/especially at clinically relevant protein-to-lipid ratios. [Figure not available: see fulltext.].
U2 - 10.1007/s11095-012-0856-8
DO - 10.1007/s11095-012-0856-8
M3 - Journal article
C2 - 22956169
SN - 0724-8741
VL - 30
SP - 140
EP - 155
JO - Pharmaceutical Research
JF - Pharmaceutical Research
IS - 1
ER -
