Synthesis of Polycaprolactone Nanoparticles through Flow‐Focusing Microfluidic‐Assisted Nanoprecipitation

Numerical simulation of fluid flow mixing in flow-focusing microfluidic devices

A numerical simulation through computational fluid dynamics is presented on the fluid flow mixing in a flow-focusing microfluidic device with three inlet channels confluence angles of 45, 67.5, and 90°. The effect of various parameters such as aspect ratio (0.5, 1, and 1.5), mixing channel length (1–4 mm), and Reynolds number (1–20) on the mixing efficiency, and the pressure drop are evaluated. The results demonstrate that the increase in mixing efficiency results from an increase in the Reynolds number and aspect ratio for all the angles. In addition, an increase in the pressure drop due to an increase in the Reynolds number and a decrease in the aspect ratio is observed. A longer length of the mixing channel indicates a higher mixing efficiency. The mixing efficiency is more suitable at an angle of 45° among the applied angles in terms of the operational and geometric parameters due to an increase in the contact surface of the flows at the inlet channels junction since the mixing index range is between 0.54 and 1 by varying the mentioned parameters.

Microfluidic Nanoparticles for Drug Delivery

Nanoparticles (NPs) have attracted tremendous interest in drug delivery in the past decades. Microfluidics offers a promising strategy for making NPs for drug delivery due to its capability in precisely controlling NP properties. The recent success of mRNA vaccines using microfluidics represents a big milestone for microfluidic NPs for pharmaceutical applications, and its rapid scaling up demonstrates the feasibility of using microfluidics for industrial-scale manufacturing. This article provides a critical review of recent progress in microfluidic NPs for drug delivery. First, the synthesis of organic NPs using microfluidics focusing on typical microfluidic methods and their applications in making popular and clinically relevant NPs, such as liposomes, lipid NPs, and polymer NPs, as well as their synthesis mechanisms are summarized. Then, the microfluidic synthesis of several representative inorganic NPs (e.g., silica, metal, metal oxide, and quantum dots), and hybrid NPs is discussed. Lastly, the applications of microfluidic NPs for various drug delivery applications are presented.

Production of doxorubicin-loaded PCL nanoparticles through a flow-focusing microfluidic device: encapsulation efficacy and drug release

The present study shows a facile route for producing doxorubicin (DOX)-loaded polycaprolactone (PCL) nanoparticles using a microfluidic device with a flow-focusing platform in a single step. Indeed, the evaluation of the performance of the flow-focusing microfluidic device for the preparation of DOX-loaded PCL (DOX/PCL) nanoparticles with a uniform size distribution and high encapsulation efficiency (EE) by applying the liquid non-solvent precipitation process is very important. Accordingly, the physicochemical characteristics of the DOX/PCL nanoparticles such as their mean size, polydispersity index (PDI), and EE were investigated by studying different parameters such as the flow rate ratio (FRR) and DOX concentration. Also, the release study was carried out at two pH of 5.5 and 7.4. The mean size of DOX/PCL nanoparticles achieved was in the range of 120-320 nm with a PDI ≤ 0.29 and EE between 48% and 87%. Moreover, the release profile of DOX/PCL nanoparticles was sustained for 10 days (≤66%) at pH 7.4. This means that the production process can result in a high EE and low release of the DOX drug.