Purpose

The size was a key factor influencing the drug loading, release, and delivery efficacies of poly (lactic-co-glycolic) acid (PLGA) microspheres (MS). The purpose of the study was to explore a novel and simple method to prepare uniform-sized PLGA MS for drug delivery.

Methods

Different from routine homogenizer, a vortex shaker was employed for emulsification during the preparation of PLGA MS. To enhance the homogeneity of resulted PLGA MS, a glass bead was used to facilitate the emulsification. The size of PLGA MS was controlled by adjusting the working frequency and time of vortex shaker. Then, selective centrifugation was used to further enrich PLGA MS of desired size. The resulted PLGA MS were systematically evaluated in anti-tubercular drug delivery.

Results

Compared with the routine stirring-based method, the novel method possessed a higher efficiency of emulsification and resulted in more homogenous MS under similar conditions. The produced PLGA particles were of a narrow size distribution, which could be 1 to 5 μm by adjusting the working frequency and time of vortex shaker. The narrow size distribution made it rather easy to enrich PLGA MS of specific size through selective centrifugation. Then, to evaluate the potential of the PLGA MS for drug delivery, 2–3-μm sized PLGA MS were selected to deliver anti-tubercular drug rifampicin (RFP). In vitro experiments demonstrated that the loaded RFP could be well-controlled release and delivered into macrophages. Anti-tubercular experiments showed that the uniform-sized MS as carriers of RFP significantly enhanced the therapeutic efficacy of the drug.

Conclusion

Collectively, the study provided a novel and simple method for preparing uniform-sized PLGA MS, which may be of potentially wide applications.

中文翻译：

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PLGA微球均匀制备的新方法及其在抗结核药物递送中的应用

目的

大小是影响聚乳酸-乙醇酸（PLGA）微球（MS）载药，释放和递送效率的关键因素。该研究的目的是探索一种新颖且简单的方法来制备均匀大小的PLGA MS，以进行药物输送。

方法

与常规均质机不同，PLGA MS的制备过程中使用涡旋振荡器进行乳化。为了增强所得PLGA MS的均匀性，使用了玻璃珠以促进乳化。PLGA MS的大小通过调整涡流振荡器的工作频率和时间来控制。然后，使用选择性离心进一步富集所需大小的PLGA MS。系统评估了所得的PLGA MS的抗结核药物递送效果。

结果

与基于常规搅拌的方法相比，该新方法具有更高的乳化效率，并在相似条件下获得了更均质的质谱。通过调节涡流振荡器的工作频率和时间，所产生的PLGA颗粒具有窄的尺寸分布，其可以为1至5μm。狭窄的尺寸分布使得通过选择性离心富集特定尺寸的PLGA MS变得相当容易。然后，为了评估PLGA MS的药物输送潜力，选择了2–3-μm大小的PLGA MS来输送抗结核药物利福平（RFP）。体外实验表明，加载的RFP可以很好地控制释放并传递到巨噬细胞中。抗结核实验表明，均一大小的MS作为RFP的载体显着增强了该药物的治疗功效。

结论

总的来说，该研究提供了一种新颖且简单的方法来制备均一尺寸的PLGA MS，可能具有广泛的应用前景。