Multilayered Nanoarchitectonics of Poly(ethylene glycol) Nanoparticles with Tunable Stiffness Modulate Bio-Nano Interactions and Targeted Drug Delivery.

Stiffness, as a crucial physicochemical property of nanoparticles (NPs), has demonstrated a significant impact on bio-nano interactions, including blood circulation, biodistribution, tumor accumulation, and cellular uptake. However, the potential role of NP stiffness in modulating bio-nano interactions to potentiate drug delivery efficacy remains largely unexplored. In this study, poly(ethylene glycol) (PEG) NPs are engineered by the sophisticated layer-by-layer (LbL) assembly approach, and the Young's moduli of NPs in the range of 2-31 kPa are tuned by control over the bilayer numbers. Notably, softer PEG NPs resulted in less adsorption of the protein corona and cell association. The half-life of blood circulation time of PEG NPs decreases along with the increase in stiffness/bilayer number of NPs, while the accumulation of PEG NPs in the liver is contrary to the case. In addition, stiffness influences the targeted drug delivery efficacy, where softer PEG NPs modified with hyaluronic acid exhibited higher cell targeting and tumor accumulation as well as better inhibition of tumor growth. This work highlights the bilayer number-mediated stiffness of NPs and the vital role of stiffness in bio-nano interactions, which provides a promising approach to design nanocarriers for improved drug delivery efficacy.