Gold nanoparticles (GNPs) have unique physical and chemical properties that allow them to function as a drug-delivery system for several tissues: skin, eye, liver, and others. However, information about the biological response of brain tissue against GNPs is limited. Astrocytes and microglia cells are the first line of defense against brain insults and proper indicators of the level of brain damage. This study was aimed to evaluate the astrocytic and microglia response after an intracerebral injection of polyethylene-glycol-coupled GNPs (PEGylated GNPs). We injected spherical PEGylated GNPs (85 × 10⁶ nanoparticles /nl) with a glass micropipette (inner diameter =35 μm) into the striatum of P60 CD1 mice. We evaluated the cellular response of astrocytes and microglia on days 3, 7, 14, 30, and 90 after intracerebral injection. For both astrocytes and microglia cells, our findings indicated that the glial response was transient and mainly circumscribed to the injection site. This evidence suggests that PEGylated GNPs are well-tolerated by the neural tissue. Understanding the effects of GNPs in the adult brain is a crucial step to design proper pharmacological vehicles to deliver long-lasting drugs.

金纳米粒子 (GNP) 具有独特的物理和化学特性，使其能够作为多种组织的药物输送系统：皮肤、眼睛、肝脏等。然而，关于脑组织对 GNP 的生物反应的信息是有限的。星形胶质细胞和小胶质细胞是抵御脑损伤的第一道防线，也是脑损伤程度的适当指标。本研究旨在评估脑内注射聚乙二醇偶联 GNP（PEG 化 GNP）后星形胶质细胞和小胶质细胞的反应。我们注入球形聚乙二醇化 GNP（85 × 10 ⁶纳米颗粒 /nl）用玻璃微量移液管（内径 = 35 μm）注入 P60 CD1 小鼠的纹状体。我们评估了脑内注射后第 3、7、14、30 和 90 天星形胶质细胞和小胶质细胞的细胞反应。对于星形胶质细胞和小胶质细胞，我们的研究结果表明胶质细胞反应是短暂的，主要局限于注射部位。这一证据表明，神经组织对 PEG 化的 GNP 具有良好的耐受性。了解 GNP 在成人大脑中的作用是设计合适的药理载体以提供长效药物的关键步骤。