Controlled assembly of gold and albumin nanoparticles to form hybrid multimeric nanomaterials

Multimeric nanoparticles (MNP) possess unique physical, chemical, and biological properties compared to monomeric NP thus, being used in applications ranging from photonic devices to cancer therapy. Despite the potential, the synthesis of well-defined MNP poses a significant challenge to scientists and remains elusive. One commonly used synthetic methodology to generate these structures is the self-assembly of individual particles. However, the surface of the individual particles in this assembly is saturated, so the esthetically beautiful structure would lack functional utility. Direct reaction of different NP is yet another way to synthesize multimeric structure. Nevertheless, the inherent reactivity of NP always results in a statistical mixture of different clusters-varying from dimeric to multimeric structure. However, the process is facile and provides opportunities to synthesize a well-defined mixture of MNP. Therefore, we used this approach to synthesize hybrid MNP composed of human serum albumin nanoparticles (HSA-NP) and gold nanoparticles (AuNP). In this MNP, each HSA-NP is attached with a median of five AuNP. The process is robust, and even the covalent attachment of dye to the surface of HSA-NP did not deter the controlled assembly. The well-defined MNP internalize within the cancer cells, whereas the aggregated nonspecific assembly failed to enter. The quantification of fluorescence in cells treated with MNP or pristine dye-labeled HSA-NP showed similar values, inferring that AuNP in MNP exhibit minimal or no influence in internalization. In summary, the synthetic process reported in this study can be used to develop MNP wherein each NP can potentially carry a drug or a reporter to combat diseases.

Automated summary

The study reports a synthetic process that can be used to develop MNP, where each NP potentially carries a drug or reporter to combat diseases. Using this method, hybrid MNP composed of HSA-NP and AuNP were synthesized, with the MNP internalizing within cancer cells while aggregated nonspecific assembly failing to enter.