A simple desolvation method for production of cationic albumin nanoparticles with improved drug loading and cell uptake

The transport protein albumin has been used as a drug nanocarrier for a long time due to its versatility. Albumin is negatively charged at physiological conditions limiting its anionic drug loading capacity. However, loading of anionic drugs in the albumin nanoparticles (NPs), can be facilitated by albumin cationization. Here, we postulate a simple desolvation method for preparation of cationic albumin NPs with improved anionic drug loading. First, bovine serum albumin was cationized with ethylenediamine. Next, salicylic acid (SA) was added to the cationic bovine serum albumin (cBSA) solution prior to the desolvation. Among different desolvating agents tested, acetonitrile allowed the highest nanoparticle formation yield. The SEM analyses showed that the average size of cBSA NPs decreased from similar to 200 nm to similar to 100 nm upon SA loading. Moreover, the drug loading capacity of cBSA NPs was found to increase similar to 2 fold, and drug release was slower compared to BSA NPs. Finally, a significant increase in cellular uptake of cBSA NPs compared to that of native BSA NPs showed the potential for improved drug delivery.