It was to study the preparation of magnetic nanoparticles (MNP)-encapsulated ropivacaine (RP) anesthesia and to explore its metabolism in mice and its effect on the function of various organs in mice. Fe₃O₄ MNP gel-encapsulated RP complex (RP–MNP) was prepared, and the content and release characteristics of RP were determined in vitro using the ultraviolet–visible spectroscopy. 30 BALB/c mice were randomly divided into 3 groups: RP-I (0.05% RP), RP-NG (1% RP encapsulated 1% RP, no Fe₃O₄ MNP), and RP-MNP (RP–MNP complex), all were injected into the tail vein with the volume of 2 mL, and there were 10 mice in each group. All mice were covered with ring and round magnets in their right paws instead of left paws. The thermal nociception test was used to detect the withdrawal latency of the left and right paws of each group of mice, and to detect the concentration of RP in plasma and ankle tissues and the cardiopulmonary function, serum biochemical indicators, and pharmacokinetic indicators of the mice in each group. The release efficiency of RP was the best at 37 °C. The withdrawal latency of right hind paw of mice in the RP-NG group was significantly lower than that in the RP-I group and the RP-MNP group in 10–80 min (P < 0.05). The withdrawal latency of right hind paw of mice in the RP-MNP group was significantly higher than that in the RP-I group in 10–60 min (P < 0.05). Compared with RP-I group, RP concentration in plasma and ankle tissue of mice in RP-NG group and RP-MNP group were significantly reduced (P < 0.05). Compared with the RP-I group and the RP-NG group, the heart rate, systolic blood pressure, diastolic blood pressure, and mean arterial pressure of the RP-MNP group were significantly reduced (P < 0.05). Compared with RP-I group and RP-MNP group, PeCO₂ and PaO₂ in RP-NG group were significantly reduced (P < 0.05). There were no significant differences in serum biochemical indicators and pharmacokinetic indicators between the three groups, such as blood urea nitrogen, alanine aminotransferase, creatine kinase, and creatinine. The drug-loaded magnetic nanoparticle RP–MNP complex, injected into mice via the tail vein and applied magnets to the ankle, can produce local anesthesia block in the ankle of mice, and its security and efficacy were higher than intravenous injection of ropivacaine alone.

旨在研究磁性纳米粒子（MNP）包封罗哌卡因（RP）麻醉剂的制备，并探讨其在小鼠体内的代谢及其对小鼠各脏器功能的影响。制备了Fe ₃ O ₄ MNP 凝胶包裹的 RP 复合物 (RP-MNP)，并使用紫外-可见光谱法在体外测定了 RP 的含量和释放特性。30只BALB/c小鼠随机分为3组：RP-I (0.05% RP), RP-NG (1% RP encapsulated 1% RP, no Fe ₃ O ₄MNP）和RP-MNP（RP-MNP复合物），均以2 mL的体积注入尾静脉，每组10只小鼠。所有小鼠的右爪而不是左爪都覆盖有环形和圆形磁铁。采用热痛觉试验检测各组小鼠左右爪的缩回潜伏期，检测血浆和踝组织中RP的浓度及小鼠的心肺功能、血清生化指标、药代动力学指标在每个组中。RP的释放效率在37℃时最好。RP-NG组小鼠右后爪缩回潜伏期10~80 min明显低于RP-I组和RP-MNP组（P < 0.05)。RP-MNP 组小鼠右后爪回缩潜伏期 10~60 min 显着高于 RP-I 组（P  < 0.05）。与 RP-I 组相比，RP-NG 组和 RP-MNP 组小鼠血浆和踝关节组织中 RP 浓度显着降低（P  < 0.05）。与 RP-I 组和 RP-NG 组相比，RP-MNP 组心率、收缩压、舒张压和平均动脉压均显着降低（P  < 0.05）。与RP-I组和RP-MNP组相比，RP-NG组PeCO ₂和PaO ₂显着降低（P < 0.05)。三组间血尿素氮、谷丙转氨酶、肌酸激酶、肌酐等血清生化指标和药代动力学指标无显着差异。载药磁性纳米粒子RP-MNP复合物经尾静脉注射入小鼠体内，在踝关节施加磁铁，可在小鼠踝关节产生局部麻醉阻滞，其安全性和有效性均高于单独静脉注射罗哌卡因。