Microfluidic encapsulation of enzymes and steroids within solid lipid nanoparticles.

The production of solid lipid nanoparticles (SLNs) is challenging, especially when considering the incorporation of biologics. A novel in-house method of microfluidic production of biologic-encapsulated SLNs is proposed, using a variety of base materials for formulation to help overcome the barriers presented during manufacture and administration. Trypsin is used as a model drug for hydrophilic encapsulation whilst testosterone is employed as a positive non-biologic lipophilic control active pharmaceutical ingredient. Particle sizes obtained ranged from 160 to 320 nm, and a lead formulation has been identified from the combinations assayed, allowing for high encapsulation efficiencies (47-90%, respectively) of both the large hydrophilic and the small hydrophobic active pharmaceutical ingredients (APIs). Drug release profiles were analysed in vitro to provide useful insight into sustained kinetics, providing data towards future in vivo studies, which displayed a slow prolonged release for testosterone and a quicker burst release for trypsin. The study represents a large leap forward in the field of SLN production, especially in the field of difficult-to-encapsulate molecules, and the technique also benefits from being more environmentally sustainable due to the use of microfluidics.

Combining 3D Printing and Microfluidic Techniques: A Powerful Synergy for Nanomedicine.

Nanomedicine has grown tremendously in recent years as a responsive strategy to find novel therapies for treating challenging pathological conditions. As a result, there is an urgent need to develop novel formulations capable of providing adequate therapeutic treatment while overcoming the limitations of traditional protocols. Lately, microfluidic technology (MF) and additive manufacturing (AM) have both acquired popularity, bringing numerous benefits to a wide range of life science applications. There have been numerous benefits and drawbacks of MF and AM as distinct techniques, with case studies showing how the careful optimization of operational parameters enables them to overcome existing limitations. Therefore, the focus of this review was to highlight the potential of the synergy between MF and AM, emphasizing the significant benefits that this collaboration could entail. The combination of the techniques ensures the full customization of MF-based systems while remaining cost-effective and less time-consuming compared to classical approaches. Furthermore, MF and AM enable highly sustainable procedures suitable for industrial scale-out, leading to one of the most promising innovations of the near future.

Microfluidic assembly of "Turtle-Like" shaped solid lipid nanoparticles for lysozyme delivery.

After two decades of research in the field of nanomedicine, nanoscale delivery systems for biologicals are becoming clinically relevant tools. Microfluidic-based fabrication processes are replacing conventional techniques based on precipitation, emulsion, and homogenization. Here, the focus is on solid lipid nanoparticles (SLNs) for the encapsulation and delivery of lysozyme (LZ) as a model biologic. A thorough analysis was conducted to compare conventional versus microfluidic-based production techniques, using a 3D-printed device. The efficiency of the microfluidic technique in producing LZ-loaded SLNs (LZ SLNs) was demonstrated: LZ SLNs were found to have a lower size (158.05 ± 4.86 nm vs 180.21 ± 7.46 nm) and higher encapsulation efficacy (70.15 ± 1.65 % vs 53.58 ± 1.13 %) as compared to particles obtained with conventional methods. Cryo-EM studies highlighted a peculiar turtle-like structure on the surface of LZ SLNs. In vitro studies demonstrated that LZ SLNs were suitable to achieve a sustained release over time (7 days). Enzymatic activity of LZ entrapped into SLNs was challenged on Micrococcus lysodeikticus cultures, confirming the stability and potency of the biologic. This systematic analysis demonstrates that microfluidic production of SLNs can be efficiently used for encapsulation and delivery of complex biological molecules.

In-House Innovative "Diamond Shaped" 3D Printed Microfluidic Devices for Lysozyme-Loaded Liposomes.

Nanotechnology applications have emerged as one of the most actively researched areas in recent years. As a result, substantial study into nanoparticulate lipidic systems and liposomes (LPs) has been conducted. Regardless of the advantages, various challenges involving traditional manufacturing processes have hampered their expansion. Here, the combination of microfluidic technology (MF) and 3D printing (3DP) digital light processing (DLP) was fruitfully investigated in the creation of novel, previously unexplored "diamond shaped" devices suitable for the production of LPs carrying lysozyme as model drug. Computer-aided design (CAD) software was used designing several MF devices with significantly multiple and diverse geometries. These were printed using a high-performance DLP 3DP, resulting in extremely high-resolution chips that were tested to optimize the experimental condition of MF-based LPs. Monodisperse narrow-sized lysozyme-loaded PEGylated LPs were produced using in-house devices. The developed formulations succumbed to stability tests to determine their consistency, and then an encapsulation efficacy (EE) study was performed, yielding good findings. The in vitro release study indicated that lysozyme-loaded LPs could release up to 93% of the encapsulated cargo within 72 h. Therefore, the proficiency of the association between MF and 3DP was demonstrated, revealing a potential growing synergy.

The Complexity of the Blood-Brain Barrier and the Concept of Age-Related Brain Targeting: Challenges and Potential of Novel Solid Lipid-Based Formulations.

Diseases that affect the Central Nervous System (CNS) are one of the most exciting challenges of recent years, as they are ubiquitous and affect all ages. Although these disorders show different etiologies, all treatments share the same difficulty represented by the Blood-Brain Barrier (BBB). This barrier acts as a protective system of the delicate cerebral microenvironment, isolating it and making extremely arduous delivering drugs to the brain. To overtake the obstacles provided by the BBB it is essential to explore the changes that affect it, to understand how to exploit these findings in the study and design of innovative brain targeted formulations. Interestingly, the concept of age-related targeting could prove to be a winning choice, as it allows to consider the type of treatment according to the different needs and peculiarities depending on the disease and the age of onset. In this review was considered the prospective contribution of lipid-based formulations, namely Solid Lipid Nanoparticles (SLNs) and Nanostructured Lipid Carriers (NLCs), which have been highlighted as able to overcome some limitations of other innovative approaches, thus representing a promising strategy for the non-invasive specific treatment of CNS-related diseases.