Effect of shape, size, and aspect ratio on nanoparticle penetration and distribution inside solid tissues using 3D...

Area of Science:

• Biomedical Engineering
• Materials Science
• Nanotechnology

Background:

• Efficient nanoparticle (NP) delivery into solid tissues is crucial for cancer therapy and diagnostics.
• While NP size and charge effects are known, the influence of NP shape and aspect ratio on intratissue transport remains poorly understood.

Purpose of the Study:

• To investigate how the nanoscale geometry of polyethylene-glycol-based anionic nanohydrogels affects their penetration and distribution within 3D spheroids, a model for tumor tissues.
• To elucidate the role of NP shape and aspect ratio in intratissue NP transport.

Main Methods:

• Fabrication of polyethylene-glycol-based anionic nanohydrogels using Jet and Flash Imprint Lithography.
• Experimental and theoretical studies of NP transport within 3D spheroids.
• Evaluation of penetration and distribution of NPs with varying shapes (disk-like, nanorods) and sizes.

Main Results:

• Low aspect ratio, disk-like cylindrical NPs (H/D ≈0.3) demonstrated maximal intratissue delivery, with over a 50% increase in cargo delivered.
• These disk-like NPs exhibited more uniform penetration compared to nanorods or smaller spherical NPs.
• In contrast, for spherical NPs, smaller size correlated with deeper and more uniform penetration.

Conclusions:

• Nanoparticle shape and aspect ratio are critical design parameters for optimizing intratissue delivery and penetration.
• Disk-like nanohydrogels show promise as superior nanocarriers for enhanced drug or contrast-agent delivery into solid tumors.
• This study provides fundamental insights into NP transport mechanisms within solid tissues, guiding future nanocarrier design.