肌苷毫微粒对成年大鼠视网膜节细胞的保护作用

目的 研究载有肌苷的毫微粒对视神经切断后视网膜节细胞(RGC)存活的影响。方法 制备肌苷毫微粒，体外测定理化性质。将等体积的肌苷毫微粒、空载毫微粒或生理盐水溶液分别注入成年大鼠左眼内，对照组未经任何治疗。1d后于眶内切断所有动物左侧视神经，术后7d取左视网膜，计数荧光金逆行标记的存活RGC。结果 肌苷毫微粒形态规整，具有缓释特点。同对照相比，肌苷毫微粒能显著提高存活RGC的密度，而空载体和生理盐水无此作用；空载毫微粒与生理盐水、对照之间以及空载毫微粒和肌苷毫微粒两组间RGC密度均无显著差异。结论 注入眼球的肌苷毫微粒至少在7d内能有效缓释肌苷，进而对轴突损伤RGC发挥显著的神经保护作用。

Neuroprotective effect of inosine-loaded nanoparticles on axotomized retinal ganglion cells in adult rats

Objective To examine the effect of inosine-loaded nanoparticles on the survival of retinal ganglion cells (RGCs) after optic nerve transection. Methods The physical and chemical properties of inosine-loaded nanoparticles prepared were measured using an emulsion polymerization method. Twelve animals received the left intraocular injections of the same volume of inosine-loaded solution or vehicle nanoparticles or normal saline, respectively. Another four animals without any treatment were taken as the control. One day later,the left optic nerves of all 16 adult rats were transected. The densities of Fluoro Gold-labeled surviving RGC were calculated in all post-fixed left retinas when the animals were euthanatized on 7 days following optic nerve transection. Results Inosine-loaded nanoparticles were round and regular in shape, and persisted in releasing inosine as indicated by the in vitro releasing test. Compared with the control animals, inosine-loaded nanoparticles significantly promoted the density of RGC survival,whereas neither vehicle nanoparticles nor saline could do so. No significant difference was detected between the vehicle nanoparticle, saline or control groups. Conclusion Inosine-loaded nanoparticles injected into eye can effectively release inosine no less than 7 days, and exhibit marked neuroprotective effect on axotomized RGC.