We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Discrepancies Between Micro Versus Macroscale Viscoelastic Properties in a Microplastic‐Tissue Composite Model
Summary
Scientists tested how tiny plastic particles change the texture of a gel designed to mimic human tissue, and found something surprising: even at very low concentrations, the plastic created stiffer zones around each particle that only showed up when measured at a cellular-sized scale, standard lab tests missed it entirely. This matters because it suggests microplastics accumulating in our organs and tissues could be subtly altering how those tissues feel and function in ways that current testing methods might overlook.
Microplastic particles (MPPs) are increasingly detected throughout the human body, yet their effects on tissue mechanics remain largely unknown. In this study, we assessed the impact of MPP loading on the mechanical properties of a gelatin–transglutaminase hydrogel network as a model of biological tissue. Compared to neat gels, bulk rheology showed a 30% increase in the storage modulus at 0.1% w/v MPP loading and tan δ rose by 400% at 1% w/v MPP loading. However, nanoindentation with cellular‐scale spatial resolution detected progressive local stiffening beginning at the lowest tested concentration of 0.001% w/v. We examined whether mechanically altered regions surrounding embedded particles could contribute to an enlarged effective filler volume by measuring the extent of the mechanically altered region surrounding individual particles, revealing a shell of elevated stiffness around included plastic beads. This thickness scaled inversely with the square of the network stiffness. Accounting for particles and shells together as enlarged effective fillers improved agreement between Guth–Gold predictions and experimental bulk rheology results. These findings demonstrate that spatially resolved mechanical measurements can detect microplastic inclusions below the detection threshold of bulk rheology, highlighting the importance of multiscale characterization when evaluating microplastic contamination.