Mechanochemically Programmed, Oligomer-Selective Amyloid Assembly via Axial Rotation

Amyloid oligomers have been widely implicated as primary cytotoxic intermediates; however, their selective and scalable production remains challenging due to rapid fibril amplification. Here, we demonstrated that sustained axial rotation enables programmable mechanochemical control over amyloid pathway selection without the use of chemical additives. Using a thermal axial rotator, native monomeric hen egg-white lysozyme was incubated at 60 {degrees}C under quantitatively tunable rotational speeds, imposing defined centrifugal forces and wall-associated shear that restructured the hydrodynamic boundary conditions. A discrete transition emerged near 600 RPM, separating the two distinct assembly regimes. Below this threshold, aggregation followed a fibril-amplifying pathway characterized by elevated {beta}-sheet content and elongated fibrillar morphologies. Above this threshold, fibrillar growth was strongly attenuated and oligomer-dominant assemblies predominated. Spectroscopic analyses and atomic force microscopy revealed that axial rotation redistributes the amyloid assembly states rather than simply suppressing aggregation. Functionally, the RPM-defined assemblies exhibited kinetically distinct seeding behaviors and induced divergent cytotoxic phenotypes in SH-SY5Y neuroblastoma cells. These findings establish axial rotation-mediated hydrodynamic boundary control as a scalable, chemical-free strategy for reprogramming amyloid assembly pathways and producing oligomer-rich assemblies with well-defined structural and functional properties.