Caco-2细胞对负载维生素D_3的纳米粒的摄入研究

The uptake of vitamin D_3 imbed by self-assembled sodium alginate nanoparticles with caco-2 cells

目的研究Caco-2细胞对负载维生素D3的、FITC标记的自组装海藻酸钠纳米粒(sSAN-VD3-FITC)的摄取及其影响因素,分析其通过Caco-2细胞吸收模型的跨膜转运特点。方法①采用激光共聚焦显微镜检测sSAN-VD3-FITC的摄取,分析作用时间的影响;②采用Caco-2细胞模型研究其跨膜转运,检测接受液的荧光强度,观察其转运特点。计算表观渗透系数(Papp),分析作用时间对转运的影响。结果①sSAN-VD3-FITC作用1 h后细胞质内出现荧光颗粒,4 h后荧光强度增强。②转运接受液的荧光强度、累积转运量较空白对照组均明显升高(P<0.05),均存在时间依赖性(P<0.05)。Papp较稳定,但随作用时间的延长逐渐减小。结论 sSAN-VD3可被Caco-2细胞摄取,并受作用时间的影响;可通过Caco-2细胞模型进行跨膜转运,并存在时间依赖性,表明其可经胃肠道给药吸收入血。

Aim To investigate the uptake of vitamin D3 imbed by self-assembled sodium alginate nanoparticles labeled by FITC（sSAN-VD3-FITC）,and the influential factors with Caco-2 cells.And to study the transmembrane transport of it with Caco-2 cell absorption model.Methods Laser scanning confocal microscope（LSCM） was utilized to exam the uptake of sSAN-VD3-FITC absorbed by Caco-2 cells.The effect of drug incubation time on the uptake was analyzed.Caco-2 cell absorption model was used to study the transmembrane transport of sSAN-VD3-FITC.The apparent permeability coefficient（Papp） was calculated and the fluorescence intensity was detected to quantitatively assay the influence of drug incubation time on the transmembrane transport.Results It took only 1h for the appearance of sSAN-VD3-FITC fluorescence particle diameter in Caco-2 cells.It was brighter when incubated for 4 h.The fluorescence intensity and the accum transport quantity of sSAN-VD3-FITC group were higher than those of the control group（P0.01）,and they were higher while the time was longer（P0.05）.Papp was fairly stabilized,but it was smaller while the time was longer.Conclusions sSAN-VD3 can be uptaken by Caco-2 cells,and can also do transmembrane transport with Caco-2 cell absorption model in a time-dependent manner.It indicates that sSAN-VD3 can be absorbed into blood via gastrointestinal tract pathway.