A fabrication method of gold coated colloidosomes and their application as targeted drug carriers

Colloidosomes have attracted considerable attention in recent years because of their potential applications in a range of industries, such as food, bioreactors and medicine. However, traditional polymer shell colloidosomes leak low molecular weight encapsulated materials due to their intrinsic shell permeability. Here, we report aqueous core colloidosomes coated with a gold shell, which make the capsules impermeable. The shells can be ruptured using ultrasound. The gold coated colloidosomes are prepared by making an aqueous core capsule with a polymer shell and then adding HAuCl4, surfactant and l-ascorbic acid to form a second shell. We propose to use the capsules as drug carriers. The gold coated colloidosomes demonstrate a low cytotoxicity and after triggering, both encapsulated doxorubicin and broken gold fragments kill cancer cells. In addition, we set up a targeting model by modifying the gold shell colloidosomes using 4,4'-dithiodibutyric acid and crosslinking them with proteins-rabbit immunoglobulin G (IgG). Label-free surface plasmon resonance was used to test the specific targeting of the functional gold shells with rabbit antigen. The results demonstrate that a new type of functional gold coated colloidosome with non-permeability, ultrasound sensitivity and immunoassay targeting could be applied to many medical applications.