Freeze-drying of Monoclonal Antibody-Conjugated Gold Nanorods: Colloidal Stability and Biological Activity

Publication date: Available online 23 August 2018Source: International Journal of PharmaceuticsAuthor(s): Majd A. Hamaly, Samer R. Abulateefeh, Khaled M. Al-Qaoud, Alaaldin M. AlkilanyAbstractMaintaining colloidal stability of nanoparticles in suspensions is a major challenge. Therefore, freeze-drying (lyophilization) is recently proposed to preserve colloidal stability of nanoparticles through maintaining them in a solid state. However, freeze-drying would itself induce nanoparticle aggregation unless proper formulation with a careful selection of cryoprotectants is considered. Herein, we evaluate the colloidal stability of gold nanorods (GNRs) conjugated with a rituximab as a model monoclonal antibody upon freeze-drying in the presence of various cryoprotectants (mannitol, trehalose and sucrose). Aggregation-induced optical responses of GNRs were used as a sensitive tool to follow nanoparticle aggregation. In the absence of cryoprotectants, rituximab-conjugated GNRs aggregate irreversibly while evaluated cryoprotectants exhibit a significant protective effect. Maximal colloidal stability of GNRs is observed in the presence of trehalose while mannitol results in best cake formation in terms of shape and integrity. A combination of trehalose and mannitol produces a lyophilized product with satisfactory GNR colloidal stability and cake shape. Moreover, we show that freeze-dried rituximab-conjugated GNRs in presence of proper cryoprotectants maintain typical binding to lymphoma...
Source: International Journal of Pharmaceutics - Category: Drugs & Pharmacology Source Type: research