Mussel Inspired Nanowire Platforms for siRNA delivery

Vertically aligned silicon nanowire (SiNW) substrates with efficient surface modifications are considered as three dimensional topological features for tissue engineering. The array of these high aspect ratio nanomaterials... [ view full abstract ]

Vertically aligned silicon nanowire (SiNW) substrates with efficient surface modifications are considered as three dimensional topological features for tissue engineering. The array of these high aspect ratio nanomaterials often act as a microenvironment for the exchange of a wide range of molecules between cells and culture substrates. High density nanowire array is found to be quite useful in reversible attachment of cells using a thermo-sensitive polymer and in vivo delivery of exogenous genes by supramolecular nanoparticles. The high density of SiNWs have significantly increased cell adhesion, proliferation and delivery of biomolecules. To achieve these goals, a proper functionalization that support cell growth and conjugation of biomolecules are required. In these contexts, mussel inspired surface chemistry using the oxidative polymerization of dopamine has secured role in the area of simple surface functionalization. Usually, 3, 4-dihydroxy-L-phenylalanine (DOPA) and lysine-rich proteins are known candidates that are responsible for the adhesion of mussels to any surface. Polymerized dopamine (PD) is capable of simply adhering to any substrates and expose prominent functional groups on the material surfaces. According to various research reports, PD coating is very stable and versatile due to covalent and non-covalent interactions. This ability of PD has opened up new opportunities for biomedical applications, including drug delivery and bio-sensing.
In this bio-inspired approach, we deployed polydopamine (PD) assisted thin layer coating on high density SiNWs to anchor more siRNA. These adsorbed siRNA offered more surface concentration for substrate-mediated delivery. We have also found that there is a cell membrane perturbation during the cell-nanowire interaction which resulted in the effective delivery siRNA into cell and allows carrying out its biological function. Our results highlights the promising application of PD-coated high dense SiNWs as simple, fast, and versatile platforms for the transmembrane delivery of biomolecules.