Multilayers and poly(allylamine hydrochloride)-graft-poly(ethylene glycol) modified bovine serum albumin nanoparticles: Improved stability and pH-responsive drug delivery

To improve the colloidal stability of bovine serum albumin (BSA) nanoparticles (NPs) in diverse mediums, poly(allylamine hydrochloride) (PAH)/sodium poly(4-styrene sulfonate) (PSS) multilayers and poly(allylamine hydrochloride)-graft-poly(ethylene glycol) (PAH-g-PEG) coating were coated on the surface of BSA NPs. Stabilities of the BSA NPs in diverse mediums with different surfaces were detected by dynamic light scattering (DLS). Multilayers and PAH-g-PEG coated BSA NPs can be well dispersed in various mediums with a narrow polydispersity index (PDI). The BSA NPs with the highest surface density of PEG show the best stability. The multilayers and PAH-g-PEG coating do not deter the pH-dependent loading and release property of BSA NPs. At pH 9, the encapsulation efficiency of doxorubicin reaches almost 99%, and the release rate at pH 5.5 is significantly higher than that at pH 7.4.