Research on the Impact of Blood Absorption on the Photothermal Effect of Nanoparticles with Protein Corona

Abstract

The protein corona (PC) formed on gold nanoparticles (AuNPs) after entering the bloodstream significantly alters their optical properties, impacting their photothermal therapy (PTT) performance. However, the quantitative mechanisms underlying the synergistic effect of blood absorption and PC on the photothermal effect of AuNPs have not been fully elucidated. This study integrates Mie scattering theory and finite element analysis to quantitatively investigate the optical cross-section, photothermal conversion efficiency (η), and temperature distribution of AuNPs and Au@PC core-shell structures in blood. Results indicate that the optical absorption cross-section of the nanoparticles exceeds their scattering cross-section, with the effect of PC on η showing a pronounced dependence on particle size. For small particles (r = 10 nm), PC formation reduces η by 90%, with minimal blood absorption impact (Δη ≤ 0.2). For larger AuNPs (r = 35 nm), PC's inhibitory effect is weaker (η reduced by 53.6%-59.4% at 15 nm PC thickness), but blood absorption effects are significantly amplified (Δη = 1.9), 9.5 times greater than in smaller particles. The lower thermal conductivity of the PC layer slows heat dissipation to surrounding blood, creating a gentler temperature gradient and effectively protecting surrounding blood. This study provides new insights into the particle size-dependent regulation of AuNP photothermal properties by blood absorption and PC interactions, offering important theoretical guidance for optimizing PTT nanomaterials and treatment strategies.