University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA.
Tuskegee University, 1200 Montgomery Rd, Tuskegee, AL, 36088, USA.
J Nanobiotechnology. 2018 Feb 12;16(1):12. doi: 10.1186/s12951-018-0339-0.
The process of optimization and fabrication of nanoparticle synthesis for preclinical studies can be challenging and time consuming. Traditional small scale laboratory synthesis techniques suffer from batch to batch variability. Additionally, the parameters used in the original formulation must be re-optimized due to differences in fabrication techniques for clinical production. Several low flow microfluidic synthesis processes have been reported in recent years for developing nanoparticles that are a hybrid between polymeric nanoparticles and liposomes. However, use of high flow microfluidic synthetic techniques has not been described for this type of nanoparticle system, which we will term as nanolipomer. In this manuscript, we describe the successful optimization and functional assessment of nanolipomers fabricated using a microfluidic synthesis method under high flow parameters.
The optimal total flow rate for synthesis of these nanolipomers was found to be 12 ml/min and flow rate ratio 1:1 (organic phase: aqueous phase). The PLGA polymer concentration of 10 mg/ml and a DSPE-PEG lipid concentration of 10% w/v provided optimal size, PDI and stability. Drug loading and encapsulation of a representative hydrophobic small molecule drug, curcumin, was optimized and found that high encapsulation efficiency of 58.8% and drug loading of 4.4% was achieved at 7.5% w/w initial concentration of curcumin/PLGA polymer. The final size and polydispersity index of the optimized nanolipomer was 102.11 nm and 0.126, respectively. Functional assessment of uptake of the nanolipomers in C4-2B prostate cancer cells showed uptake at 1 h and increased uptake at 24 h. The nanolipomer was more effective in the cell viability assay compared to free drug. Finally, assessment of in vivo retention in mice of these nanolipomers revealed retention for up to 2 h and were completely cleared at 24 h.
In this study, we have demonstrated that a nanolipomer formulation can be successfully synthesized and easily scaled up through a high flow microfluidic system with optimal characteristics. The process of developing nanolipomers using this methodology is significant as the same optimized parameters used for small batches could be translated into manufacturing large scale batches for clinical trials through parallel flow systems.
优化和制备纳米颗粒用于临床前研究的过程可能具有挑战性且耗时。传统的小规模实验室合成技术存在批次间变异性。此外，由于临床生产中制造技术的差异，原始配方中使用的参数必须重新优化。近年来，已有几种用于开发介于聚合物纳米颗粒和脂质体之间的纳米颗粒的低流速微流控合成工艺得到了报道。然而，尚未有报道使用高通量微流控合成技术用于此类纳米颗粒体系，我们将其称为纳米脂质体。在本手稿中，我们描述了使用高通量微流控合成方法成功优化和功能评估了在高流速参数下制备的纳米脂质体。
发现这些纳米脂质体的最佳总合成流速为 12 ml/min，流速比为 1:1（有机相：水相）。PLGA 聚合物浓度为 10 mg/ml，DSPE-PEG 脂质浓度为 10%w/v 提供了最佳的粒径、PDI 和稳定性。优化了代表性疏水分子药物姜黄素的载药和包封，发现当姜黄素/PLGA 聚合物的初始浓度为 7.5%w/w 时，可实现 58.8%的高包封效率和 4.4%的载药量。优化后的纳米脂质体的最终粒径和多分散指数分别为 102.11nm 和 0.126。在 C4-2B 前列腺癌细胞中摄取纳米脂质体的功能评估表明，在 1 小时时摄取增加，在 24 小时时摄取增加。与游离药物相比，纳米脂质体在细胞活力测定中更有效。最后，在小鼠体内评估这些纳米脂质体的保留情况表明，在 2 小时内保留，在 24 小时内完全清除。
在这项研究中，我们已经证明，通过高通量微流控系统可以成功地合成纳米脂质体配方，并可以轻松放大，且具有最佳特性。使用这种方法开发纳米脂质体的过程意义重大，因为可以将用于小批次的相同优化参数转化为通过平行流系统用于临床试验的大规模批次生产。
