Assembly of Multicomponent Nano-Bioconjugates Composed of Mesoporous Silica Nanoparticles, Proteins, and Gold Nanoparticles

Abstract

The purpose of this work was the assembly of multicomponent nano-bioconjugates based on mesoporous silica nanoparticles (MSNs), proteins (bovine serum albumin, BSA, or lysozyme, LYZ), and gold nanoparticles (GNPs). These nano-bioconjugates may find applications in nanomedicine as theranostic devices. Indeed, MSNs can act as drug carriers, proteins stabilize MSNs within the bloodstream, or may have therapeutic or targeting functions. Finally, GNPs can either be used as contrast agents for imaging or for photothermal therapy. Here, amino-functionalized MSNs (MSN–NH 2 ) were synthesized and characterized through various techniques (small angle X-rays scattering TEM, N 2 adsorption/desorption isotherms, and thermogravimetric analysis (TGA)). BSA or lysozyme were then grafted on the external surface of MSN–NH 2 to obtain MSN–BSA and MSN–LYZ bioconjugates, respectively. Protein immobilization on MSNs surface was confirmed by Fourier transform infrared spectroscopy, ζ-potential measurements, and TGA, which also allowed the estimation of protein loading. The MSN–protein samples were then dispersed in a GNP solution to obtain MSN–protein–GNPs nano-bioconjugates. Transmission electron microscopy (TEM) analysis showed the occurrence of GNPs on the MSN–protein surface, whereas almost no GNPs occurred in the protein-free control samples. Fluorescence and Raman spectroscopies suggested that proteins–GNP interactions involve tryptophan residues.

Gold Nanomaterials for Imaging-Guided Near-Infrared in vivo Cancer Therapy

“…Due to the facile surface chemistry properties, functional groups can combined with gold nanomaterials through weak interactions and the stable covalent anchors (Kou et al, 2009; Moraes Silva et al, 2016; Zou et al, 2016; Wang K. et al, 2017). So far, many modification approaches have been introduced by covering and ligand exchange, so gold nanoparticles can be modified with biopolymer (e.g., polyethylene glycol (PEG), oligonucleotides, antibodies, peptides) (Loh et al, 2016; Chen Y. et al, 2017; Anantha-Iyengar et al, 2019; Delpiano et al, 2019), hydrophobic drug molecules (e.g., paclitaxel, cisplatin, tamoxifen, doxorubicin) (Avitabile et al, 2018; Ma et al, 2018), biofunctional molecules (chitosan, silica, folic acid, polyunsaturated fatty acids, and hyaluronic acid, etc.) (Vigderman and Zubarev, 2013; Sztandera et al, 2019) and other amphiphilic ligands through functional bridges, such as thiol ligands (e.g., thiolate, dithiolate, thioctic acid), amino, and carboxyl moieties (Figure 1) (Daraee et al, 2014; Kong et al, 2017).…”

Advances in the application of gold nanoparticles in bone tissue engineering

“…With the development of the research, a mesoporous silica-gold nanorods system has been developed, which is a multilayered structure by layer-by-layer assembly with rotational diffusion and adjustable size [47]. When assembled with proteins, the system with high porosity and biocompatibility can function as both the targeted drug carrier and medical imaging contrast agent [48]. What's even more exciting is that the surface encapsulation of silica gel shell could inhibit the cytotoxicity of GNPs used in cells [49].…”

Gold Nanoparticles: A Powerful Tool to Visualize Proteins on Ordered Mesoporous Silica and for the Realization of Theranostic Nanobioconjugates

“…GNPs are indeed characterized by a surface plasmon frequency in the visible range, which makes them suitable for therapeutic treatments (i.e., photothermal therapy [ 62 ] or, more interestingly, for “theranostics” that is the combination between therapy and diagnostics [ 63 ]. In a very recent work [ 64 ], we assembled multicomponent nano-bioconjugates based on mesoporous silica nanoparticles (MSNs), proteins (BSA or lysozyme), and gold nanoparticles ( Figure 10 ). The purpose of the realization of such nano-bioconjugates was for a possible application in nanomedicine as theranostic devices.…”