Table 1.
Nanoemulsion composition and indices.
Table 2.
Initial dynamic light scattering analysis of nanoemulsions.
Fig 1.
Frequency of nanoemulsion droplet sizes in heat sterilized preparations.
Data obtained from Cryo-TEM image analysis. Nanoemulsions without added perfluorodecylbromide (23 and 63) show a broader size distribution that is shifted to bigger droplets as compared to nanoemulsions containing 3% perfluorodecylbromide (20/3 and 60/3). This indicates a stabilizing effect of perfluorodecylbromide in heat sterilization.
Fig 2.
Box plot diagrams revealing droplet size distribution of nanoemulsions.
Box plots show the development of droplet sizes over storage time for four nanoemulsions. Boxes represent droplet sizes with a probability between 25 and 75%, the line ▬ inside the box is for the median size. Mean diameter is indicated with a bullet ● and whiskers are for a probability of 5 (┴) or 95 (┬) % respectively. An arrow pointing downwards (▼) indicates the 1% value whereas an arrow pointing upwards (▲) represents the 99% probability of particle diameter. (A) is the nanoemulsion containing 23% perfluorooctylbromide (23), (B) the nanoemulsion with 20% perfluorooctylbromide and 3% perfluorodecylbromide (20/3). (C) represents the nanoemulsion with 63% perfluorooctylbromide (63) and (D) the one with 60% perfluorooctylbromide and 3% perfluorodecylbromide (60/3). Nanoemulsions lacking perfluorodecylbromide (A and C) show a broader size distribution and bigger mean size than their comparative nanoemulsions with stabilizing perfluorodecylbromide (B and D).
Table 3.
DLS and Cryo-TEM data of stored nanoemulsions.
Fig 3.
Sample Cryo-TEM images of perfluorocarbon-nanoemulsions.
(A) Image of a nanoemulsion containing 23% w/w perfluorooctylbromide, after heat sterilization. Nanoemulsion droplets appear as dark vesicles, liposomes are visible to a hugh number as smaller, light vesicles. Scale bar is 500 nm. (B) shows the same nanoemulsion after 50 weeks storage at 4°C. Though the scale bar is 1 μm in this image, increased size of droplets can easily be observed. The number of liposomes seems to be stepped up. In (C) a nanoemulsion containing 20% perfluorooctylbromide and 3% perfluorodecylbromide after heat sterilization is depicted. Though a huge number of liposomes can be detected, more and smaller nanoemulsion droplets are visible than compared to image (A). All samples were diluted in the same ratio with sample buffer.