Human serum albumin corona on functionalized gold nanorods modulates doxorubicin loading and release

Abstract

Gold nanorods (AuNRs) have potential widespread applications in diverse biomedical fields. However, under physiological conditions, protein corona formation on these AuNRs is inevitable. Human serum albumin (HSA), being the most abundant serum protein, tends to act like a reservoir for holding various therapeutic payloads. In the current study, we utilized the protein corona formed by HSA on differently functionalized (CTAB, PSS, and PEG) AuNRs for doxorubicin loading. Parameters such as surface functionalization of the AuNRs, amount and pattern of HSA corona influenced doxorubicin loading. The doxorubicin loading pattern was found to be in the order PSS–AuNRs > CTAB–AuNRs > PEG–AuNRs. Corona formation and doxorubicin loading modulated the absorption spectral peaks, mean hydrodynamic diameter, and surface charge of the functionalized AuNRs. The pH-responsiveness and sustained release behavior of the drug-loaded coronated particles were evaluated. A payload leakage study over a period of 14 days indicated that both surface functionalization and amount of bound corona had a combinatorial effect on the retention of drug payload. Additionally, the influence of bound payload on the stability of the corona was also analyzed. Finally, a biocompatibility assessment was done using a hemolytic assay where the presence of HSA corona was seen to be advantageous in preventing excessive RBC membrane damage. The study highlights the relevance and probable applications of protein-coronated gold nanorods with ideal surface functionalization as a new nanoplatform for drug delivery.