Fabrication of Doxorubicin-Loaded Lipid-Based Nanocarriers by Microfluidic Rapid Mixing

Comparing continuous micromixing and extrusion downsizing for PEGylated nanoliposomes remotely loaded with doxorubicin or the steroid pro-drug methylprednisolone hemisuccinate

Since the FDA approval of the first nanodrug Doxil® in 1995, twenty subsequent liposome and lipid nanoparticle (LNP) based drugs (of which 10 are nanodrugs), were approved by the FDA. The application of such drug-products was considerably boosted by the mRNA-LNP based vaccines used to stop the COVID-19 pandemic. Research on lipid-based vesicles and nanoparticles for drug delivery dates to the 1970s and has culminated in both continuous flow and extrusion-based fabrication processes for current state-of-the-art GMP industrial production of nanoliposomes and lipid nanoparticles. In this study, we compare these two approaches for the preparation of two PEGylated nanoliposome-based drug-products, keeping all other production steps leading to the final drug-product identical. One of these products, generic Doxil®, is remotely and actively loaded with the anthracycline doxorubicin (an amphipathic weak base) driven by a transmembrane ammonium gradient, while the other is methylprednisolone hemisuccinate (an amphipathic weak acid) remotely and actively loaded via a transmembrane acetate gradient. We demonstrate that a microfluidics-based micromixer approach yields equivalent or even better drug-products, especially since the downsizing by microfluidics is not performed above the temperature range of lipid phase transition. The main difference in the physico-chemical features is that size distribution of the microfluidics prepared PEGylated nano liposomes was significantly narrower and morphological analysis by cryo-TEM confirmed higher homogeneity. An additional advantage of the microfluidic approach is that it is a continuous production. Therefore, it enables the direct production of large volumes of high-quality nano-liposomal based drug-products.

Advances in microscopy characterization techniques for lipid nanocarriers in drug delivery: a comprehensive review

This review paper provides an in-depth analysis of the significance of lipid nanocarriers in drug delivery and the crucial role of characterization techniques. It explores various types of lipid nanocarriers and their applications, emphasizing the importance of microscopy-based characterization methods such as light microscopy, confocal microscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The paper also delves into sample preparation, quantitative analysis, challenges, and future directions in the field. The review concludes by underlining the pivotal role of microscopy-based characterization in advancing lipid nanocarrier research and drug delivery technologies.

Microfluidic-derived docosahexaenoic acid liposomes for glioblastoma therapy

Glioblastoma (GBM) is the most prevalent malignant primary brain tumor and currently lacks an effective treatment. In this study, we utilized a microfluidic system to synthesize docosahexaenoic acid (DHA) liposomes for GBM therapy. DHA is an omega-3 (ω3) polyunsaturated fatty acid commonly found in human dietary consumption that has demonstrated potential in mitigating cancer development. The microfluidic device employed allowed for precise fine-tuning of the physicochemical properties of liposomes by adjusting the flow rate ratios, flow rates, and lipid concentrations. Three distinct-sized liposomes, ranging from 80 nm and 130 nm, were successfully internalized by GBM cells, and demonstrated the ability to reduce the viability of these cells. Furthermore, DHA liposomes proved significantly more efficient in triggering apoptotic pathways, through caspase-3-dependent mechanisms, in comparison to free DHA. Thus, the nanomedicine platform established in this study presents new opportunities in the development of liposome formulations incorporating ω3 fatty acids for cancer therapy.

Microfluidics for nano-drug delivery systems: From fundamentals to industrialization

In recent years, owing to the miniaturization of the fluidic environment, microfluidic technology offers unique opportunities for the implementation of nano drug delivery systems (NDDSs) production processes. Compared with traditional methods, microfluidics improves the controllability and uniformity of NDDSs. The fast mixing and laminar flow properties achieved in the microchannels can tune the physicochemical properties of NDDSs, including particle size, distribution and morphology, resulting in narrow particle size distribution and high drug-loading capacity. The success of lipid nanoparticles encapsulated mRNA vaccines against coronavirus disease 2019 by microfluidics also confirmed its feasibility for scaling up the preparation of NDDSs via parallelization or numbering-up. In this review, we provide a comprehensive summary of microfluidics-based NDDSs, including the fundamentals of microfluidics, microfluidic synthesis of NDDSs, and their industrialization. The challenges of microfluidics-based NDDSs in the current status and the prospects for future development are also discussed. We believe that this review will provide good guidance for microfluidics-based NDDSs.

Use of Microfluidics to Prepare Lipid-Based Nanocarriers

Lipid-based nanoparticles (LBNPs) are an important tool for the delivery of a diverse set of drug cargoes, including small molecules, oligonucleotides, and proteins and peptides. Despite their development over the past several decades, this technology is still hindered by issues with the manufacturing processes leading to high polydispersity, batch-to-batch and operator-dependent variability, and limits to the production volumes. To overcome these issues, the use of microfluidic techniques in the production of LBNPs has sharply increased over the past two years. Microfluidics overcomes many of the pitfalls seen with conventional production methods, leading to reproducible LBNPs at lower costs and higher yields. In this review, the use of microfluidics in the preparation of various types of LBNPs, including liposomes, lipid nanoparticles, and solid lipid nanoparticles for the delivery of small molecules, oligonucleotides, and peptide/protein drugs is summarized. Various microfluidic parameters, as well as their effects on the physicochemical properties of LBNPs, are also discussed.

Editorial for the Specific Issue: “Lipid-Based Nanocarriers”

Small molecules and biologics are the two major categories of active pharmaceutical ingredients (APIs) commonly used for disease management [...]