The mechanism of uptake of biodegradable microparticles in Caco-2 cells is size dependent
The mechanism of uptake of biodegradable microparticles in Caco-2 cells is size dependent
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DOI：
10.1023/a:1012126301290
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发表时间：
1997-11-01
影响因子：
3.7
通讯作者：
Amidon, GL
中科院分区：
文献类型：
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作者：
Desai, MP;Labhasetwar, V;Amidon, GL
目的.研究生物可降解微粒在Caco-2细胞中的摄取。通过多重乳液技术配制平均直径为0.1 μ m、1 μ m和10 μ m的聚乳酸聚乙醇酸共聚物（PLGA 50：50）的生物可降解微粒，其含有作为模型蛋白的牛血清白蛋白和作为荧光标记的6-香豆素。将Caco-2细胞单层与每种直径的微粒（100 μ g/ml）孵育2小时。Caco-2细胞中的微粒摄取通过共聚焦显微镜和还通过定量由细胞摄取的微粒的6-香豆素含量来研究。研究了微粒子浓度、孵育时间和温度对微粒子细胞摄取的影响。研究表明，Caco-2细胞微粒摄取显著依赖于微粒直径。以重量计，0.1 μ m直径的微粒的吸收比1 μ m直径的微粒大2.5倍，比10 μ m直径的微粒大6倍。类似地，就数量而言，0.1 μ m直径微粒的吸收比1 μ m直径微粒大2.7 × 10（3）倍，比10 μ m直径微粒大6.7 × 10（6）倍。在100 μ g/ml浓度下，0.1 μ m直径微粒的吸收效率为41%，而1 μ m和10 μ m直径微粒的吸收效率分别为15%和6%。Caco-2细胞微粒（0.1 μ m）的摄取在100 μ g/ml至500 μ g/ml范围内随浓度增加，然后在更高浓度下达到平台。微粒的摄取随孵育时间增加，在两小时时达到稳定状态。在37摄氏度的孵育温度下的摄取量大于在4摄氏度的摄取量。Caco-2细胞微粒摄取是微粒直径、浓度、孵育时间和温度依赖性的。与较大直径的微粒相比，小直径微粒（0.1 μ m）具有显著更大的摄取。因此，结果表明，微粒在Caco-2细胞中的摄取机制是粒径依赖性的。Caco-2细胞被用作胃肠道摄取的体外模型，因此在这些研究中获得的结果可能在优化基于微粒的口服药物递送系统中具有重要意义。
Purpose. To study the uptake of biodegradable microparticles in Caco-2 cells.Methods. Biodegradable microparticles of polylactic polyglycolic acid co-polymer (PLGA 50:50) of mean diameters 0.1 mu m, 1 mu m, and 10 mu m containing bovine serum albumin as a model protein and 6-coumarin as a fluorescent marker were formulated by a multiple emulsion technique. The Caco-2 cell monolayers were incubated with each diameter microparticles (100 mu g/ml) for two hours. The microparticle uptake in Caco-2 cells was studied by confocal microscopy and also by quantitating the 6-coumarin content of the microparticles taken up by the cells. The effects of microparticle concentration, and incubation time and temperature on microparticle cell uptake were also studied.Results. The study demonstrated that the Caco-2 cell microparticle uptake significantly depends upon the microparticle diameter. The 0.1 mu m diameter microparticles had 2.5 fold greater uptake on the weight basis than the 1 mu m and 6 fold greater than the 10 mu m diameter microparticles. Similarly in terms of number the uptake of 0.1 mu m diameter microparticles was 2.7 x 10(3) fold greater than the 1 mu m and 6.7 x 10(6) greater than the 10 mu m diameter microparticles. The efficiency of uptake of 0.1 mu m diameter microparticles at 100 mu g/ml concentration was 41% compared to 15% and 6% for the I mu m and the 10 mu m diameter microparticles, respectively. The Caco-2 cell microparticle (0.1 mu m) uptake increased with concentration in the range of 100 mu g/ml to 500 mu g/ml which then reached a plateau at higher concentration. The uptake of microparticles increased with incubation time, reaching a steady state at two hours. The uptake was greater at an incubation temperature of 37 degrees C compared to at 4 degrees C.Conclusions. The Caco-2 cell microparticle uptake was microparticle diameter, concentration, and incubation time and temperature dependent. The small diameter microparticles (0.1 mu m) had significantly greater uptake compared to larger diameter microparticles. The results thus suggest that the mechanism of uptake of microparticles in Caco-2 cell is particle diameter dependent. Caco-2 cells are used as an in vitro model for gastrointestinal uptake, and therefore the results obtained in these studies could be of significant importance in optimizing the microparticle-based oral drug delivery systems.