Tuning Nanoparticle Rigidity: From Megadalton Dendritic Dots to Mechanobiology-Driven Nano-Bio Interactions

Area of Science:

• Biomaterials Science
• Nanotechnology
• Mechanobiology

Background:

• Nanoparticle rigidity is a key factor in nano-bio interactions, but its effects are difficult to isolate from other properties like size and charge.
• Understanding nanoparticle mechanics is crucial for designing effective drug delivery systems.

Purpose of the Study:

• To synthesize and systematically study the effects of tunable rigidity in dendrimers on biological interactions.
• To decouple the influence of rigidity from size and charge in nanoparticle behavior.

Main Methods:

• Synthesis of ultrahigh-generation dye-cored polylysine dendritic dots (PDDs) with controlled rigidity (0.93-1.90 GPa).
• Gram-scale production of PDDs with consistent size and charge but varying stiffness.
• Evaluation of PDDs' cellular uptake, transcytosis, blood circulation, tumor penetration, and accumulation in 3D tumor spheroids.

Main Results:

• A mechanobiological trade-off was observed: stiffer PDDs showed enhanced cellular uptake, transcytosis, and penetration in 3D tumor spheroids.
• Softer PDDs demonstrated prolonged blood circulation times and superior tumor accumulation.
• PDDs provided a model system to study rigidity effects in megadalton dendrimers.

Conclusions:

• Nanoparticle rigidity plays a dual role in nano-bio interactions, influencing both cellular processes and biodistribution.
• PDDs serve as a valuable tool for mechanobiology research.
• The findings offer design principles for developing advanced drug delivery systems based on tunable nanoparticle rigidity.