Self-assembly of lipid corona on biocompatible gold nanoparticle suprastructures with plasmonic and theranostic functions

Lipid-based carriers represent the leading technology for nanoparticle (NP) drug delivery. To this end, the incorporation of gold NPs into lipid coronas (LC) has long been of scientific and practical interest. However, challenges persist in confining the inorganic payload within the LC, while achieving high loading efficiency and control over the surface functionalization of Au NPs. Here, phospholipids are self-assembled on Au NPs suprastructures, generating lipid-coated nanoconstructs at an Au loading>90% in mass and maintaining the desired functionalization of the gold surface with 4-mercaptophenylboronic acid (MPBA). The resulting LC-MPBA-Au NPs exhibit the colloidal behaviour of the lipid vesicles together with the plasmonic properties of the Au suprastructures. According to molecular dynamics calculations, the phospholipids readily assemble on Au nanoparticle aggregates, with MPBA favouring the process. In addition, calculations suggest that surface corrugation of Au suprastructures promotes lipid coating. This indicates that preformed Au suprastructures characterized by surface irregularities are essential for attaining optimal loading efficiency within the LC. These nanohybrids hold significant promise for multimodal theranostics, as they combine high biocompatibility and efficient cellular uptake, can be tracked by computed tomography imaging, and possesses the physical characteristics of a bimodal radiosensitizer suitable for two complementary radiotherapy modalities based on X-ray irradiation and boron neutron capture.