The glomerular filtration barrier is known as a ‘size cutoff’ slit, which retains nanoparticles or proteins larger than 6–8 nm in the body and rapidly excretes smaller ones through the kidneys. However, in the sub-nanometre size regime, we have found that this barrier behaves as an atomically precise ‘bandpass’ filter to significantly slow down renal clearance of few-atom gold nanoclusters (AuNCs) with the same surface ligands but different sizes (Au₁₈, Au₁₅ and Au_10-11). Compared to Au₂₅ (∼1.0 nm), just few-atom decreases in size result in four- to ninefold reductions in renal clearance efficiency in the early elimination stage, because the smaller AuNCs are more readily trapped by the glomerular glycocalyx than larger ones. This unique in vivo nano–bio interaction in the sub-nanometre regime also slows down the extravasation of sub-nanometre AuNCs from normal blood vessels and enhances their passive targeting to cancerous tissues through an enhanced permeability and retention effect. This discovery highlights the size precision in the body's response to nanoparticles and opens a new pathway to develop nanomedicines for many diseases associated with glycocalyx dysfunction.

肾小球滤过屏障被称为“尺寸截止”狭缝，它将大于 6-8 nm 的纳米颗粒或蛋白质保留在体内，并通过肾脏快速排出较小的纳米颗粒或蛋白质。然而，在亚纳米尺寸范围内，我们发现该屏障充当原子级精确的“带通”滤波器，可显着减慢具有相同表面配体但不同尺寸（AuNC）的少原子金纳米簇（AuNC）的肾脏清除率。 ₁₈ 、Au ₁₅和 Au _10-11 )。与 Au ₂₅ ( ~ 1.0 nm) 相比，仅几个原子的尺寸减小就会导致早期消除阶段的肾脏清除效率降低四到九倍，因为较小的 AuNC 比较大的 AuNC 更容易被肾小球糖萼捕获。这种亚纳米范围内独特的体内纳米-生物相互作用也减慢了亚纳米AuNC从正常血管的外渗，并通过增强的渗透性和保留效应增强其对癌组织的被动靶向。这一发现强调了人体对纳米颗粒反应的尺寸精度，并为开发纳米药物治疗许多与糖萼功能障碍相关的疾病开辟了一条新途径。