Four fatty acid-solid lipid nanoparticles (SLNs) were formulated and evaluated for intracellular delivery, accumulation, as well as discrepancy in antimicrobial efficacy of their loaded enrofloxacin by using RAW 264.7 cells. The delivery efficacy of enrofloxacin into the macrophages by docosanoic acid SLNs (DAS), octadecanoic acid SLNs (OAS), hexadecanoic acid SLNs (HAS), and tetradecanoic acid SLNs (TAS) were 26.1–29.0, 9.3–10.3, 4.7–5.3 and 4.5–5.0 folds, respectively, compared to free drug when co-incubation for 0.25−4 h. The longer fatty acid prepared nanoparticles loaded enrofloxacin eliminated more slowly and accumulated in the cells for a longer time.The confocal microscopy also demonstrated that higher amount of fatty acid SLNs entered the cells with stronger accumulation performance and less amount SLNs absorbed on the cytomembrane as the carbon chain of fatty acids increased. The bactericidal activity of the four fatty acid SLNs against intracellular Salmonella CVCC541 significantly enhanced compared to the free enrofloxacin. These results revealed that fatty acid SLNs, especially docosanoic acid nanoparticles, might be effective nanocarriers to ferry enrofloxacin or other lipid soluble drugs into cells for intracellular bacterial infection treatment.

配制了四个脂肪酸固体脂质纳米颗粒（SLN），并通过使用RAW 264.7细胞评估了其负载的恩诺沙星的细胞内递送，累积以及抗菌功效的差异。恩氟沙星的递送效力成二十二烷酸前哨淋巴结（DAS），十八烷酸前哨淋巴结（OAS），十六烷酸前哨淋巴结（HAS），和十四烷酸前哨淋巴结的巨噬细胞（TAS）分别为26.1 - 29.0，9.3-10.3，4.7-5.3和4.5 –共孵育0.25-4 h时，与游离药物相比，分别为5.0倍。用恩诺沙星负载的更长的脂肪酸制备的纳米颗粒消除速度较慢，并在细胞中积累了更长的时间。共聚焦显微镜还表明，大量的脂肪酸SLNs进入细胞时具有较强的积累性能，而较少的SLNs则被细胞膜吸收。脂肪酸碳链增加。四种脂肪酸SLNs对细胞内沙门氏菌CVCC541的杀菌活性与游离恩诺沙星相比显着增强。这些结果表明，脂肪酸SLNs，尤其是二十二烷酸纳米颗粒，可能是将恩诺沙星或其他脂溶性药物运送到细胞内以进行细胞内细菌感染治疗的有效纳米载体。