Chiral Nanoparticle Geometry for Enhanced Vascular Margination: A First-Principles Derivation and Complete Research Framework for RBC-Mediated Circulating Tumour Cell Targeting

This work presents a comprehensive theoretical and methodological framework investigating nanoscale helical nanoparticle geometries as passive hydrodynamic biasing structures for enhanced vascular margination and Circulating Tumour Cell (CTC) targeting. The central hypothesis proposes that chiral geometric anisotropy may bias Red Blood Cell (RBC)-mediated collision dynamics in non-equilibrium blood flow, increasing near-wall residence probability relative to conventional spherical nanoparticles — without violating Purcell's Scallop Theorem. The margination velocity scaling law is derived from physical first principles using Resistive Force Theory (RFT) and Jeffery orbit analysis, yielding a dimensionless chirality parameter χ_RFT = [(β−1)/(β+1)] × [λ²/(λ²+1)] × sin(θ_h)cos(θ_h), with a numerical estimate of χ_RFT ≈ 0.073 and predicted margination drift of 0.05–0.5 μm/s at physiological shear rates. The document additionally proposes a differential cooperative avidity targeting strategy combining EpCAM-associated epithelial targeting, cell-surface Vimentin (CSV)-associated mesenchymal targeting, and leukocyte evasion via CD47 signalling and steric PEG exclusion. A dual metabolic inhibition payload strategy is discussed alongside its known clinical limitations. A complete research roadmap is provided including fabrication protocols (GLAD and chiral polymer templating), surface functionalisation chemistry, computational validation methodology (CFD, Lattice Boltzmann), microfluidic experimental protocols, in-vivo study design, and clinical translation pathway through Phase I trial design. This work is intended strictly as a hypothesis-generating theoretical framework requiring experimental validation.