Using DLS, we found that the average size of our fabricated nanoliposome decreased from 180 to 140 nm, however we did not find any reason for it. The drug was a monoclonal antibody.
Dear Dina
I wish you mentioned the PDI value in each case.
Nevertheless, if you are entirely sure about: 1- the validity of DLS results, 2- the similarity between the way of representing the hydrodynamic size before and after drug loading (the same parameter in vertical axis in both) 3- use of the same dilution buffer in both DLS tests and 4- the reproducibility of liposome formation in terms of size and so on, on my mind, two likely reasons could be considered: a) the change in the structure and intermolecular interactions in liposomes caused during the drug loading process, especially when the "active" loading is employed. b) the change in apparent polar area of phospholipids via a robust interaction by antibodies and thus, alteration in critical packing parameter of phospholipids which would have a momentous effect on morphology and size of liposomes.
Further studies using TEM or FE-SEM is advised. Good luck
Can you share the data file for the two situations, i.e. the 180nm and the 140nm measurements? If you have a Zetasizer Nano you can find the raw dts file as described in https://www.materials-talks.com/faq-how-can-i-submit-a-data-file-to-the-help-desk/ . There is also a way to create a new file with just a selection of records, i.e. the two of interest. If you happen to also measured the zeta potential, did the conductivity of the sample change between the two points? Is the sample stable otherwise? Potential influences can be time, storage temperature, storage container, pH,...
The comparison of the autocorrelation functions could can help to understand your result , more precisely: if the shape of the autocorrelation functions stays the same and if there is the shift of the decay to the smaller time (see example of shift in attached image).
- Badges
- Science method