纳米金促进神经营养因子-3透皮实验研究

目的 探讨纳米金颗粒(gold nanoparticles,AuNP)运载神经营养因子-3(neurotrophin-3,NT3)透皮的效果及其对皮下神经的作用,以开发具有透皮作用的纳米金载药体系.方法 通过共价偶联方式,将His标记的NT3与纳米金共价偶联,应用于动物皮肤组织.实验分为空白对照组、金纳米颗粒与牛血清蛋白结合(AuNP-CONH-BSA)组、金纳米颗粒与NT3结合(AuNP-CONH-NT3)组和NT3注射组.利用抗His抗体进行免疫组化分析其透皮效果,同时利用免疫组化对神经丝蛋白(neuropeptide,NF200)阳性细胞进行检测,分析载药体系对皮下神经的作用.结果 透皮24 h后免疫组化分析结果显示,在实验组AuNP-CONH-NT3组和NT3注射组中均检测到了NT3,而空白对照组和AuNP-CONH-BSA组中则未检测到;在透皮1个月和3个月免疫组化分析结果显示,AuNP-CONH-NT3组NF200阳性细胞数量所占百分比明显高于空白对照组和AuNP-CONH-BSA组(P＜0.01),而与NT3注射组比较,差异无统计学意义(P＞0.05).结论 构建的AuNP-CONH-NT3具有很好的透皮效果,可以促进神经再生.

Transdermal penetration of gold nanoparticles carrying neurotrophic factor-3 through mouse skin

Objective The skin as a natural barrier not only protects the body from invasion by foreign substances or organisms but also prevents effective entry of macromolecular drugs.In this study we tested the transdermal penetration of gold nanoparticles (AuNP) carrying neurotrophin-3 (NT3) and its effect on subcutaneous nerves.Methods His-marked NT3 or bovine serum albumin (BSA) was covalently coupled with AuNP to synthesize the conjugate AuNP-CONH-NT3 or AuNP-CONH-BSA.With NT3 as the positive control and PBS as the negative control,the transdermal penetration of the two conjugates was tested on the dorsal skin of mice using immunohistochemistry with anti-His antibody.Immunohistochemistry was also used for detecting neuropeptide NF200-positive cells to analyze the effect of the drug delivery system on the subcutaneous nerves.Results Twenty-four hours after application of the synthesized conjugates,NT3 or PBS on the dorsal skin of the mice,immunohistochemistry detected the presence of NT3 in the skin tissues in AuNP-CONH-NT3 group and NT3 group,but not in the control group or AuNP-CONH-BSA group.At 1 month and 3 months after the application,immunohistochemical analysis revealed a significantly higher percentage of NF200-positive cells in AuNP-CONH-NT3 group than in both control group and AuNP-CONH-BSA group (P ＜ 0.01);the percentages of the positive cells were similar between AuNP-CONH-NT3 group and NT3 group (P ＞ 0.05).Gonclusion AuNP-CONH-NT3 allows efficient transdermal penetration of NT3 to promote nerve regeneration.