Computational Prodrug Design Methodology for Liposome Formulability Enhancement of Small-Molecule APIs

The 8th International Symposium on Phospholipids in Pharmaceutical Research - An update on current research in phospholipids presented at the biennial symposium of the Phospholipid Research Center Heidelberg

This Conference Report recaps recent advances in the research on phospholipids and their applications for advanced drug delivery and analytical purposes that have been presented at the "8th International Symposium on Phospholipids in Pharmaceutical Research" of the Phospholipid Research Center (PRC), held from September 09-11, 2024, at the University of Heidelberg, Germany. The PRC is a non-profit organization focused on expanding and sharing scientific and technological knowledge of phospholipids in pharmaceutical and related applications. This is accomplished by, e.g., funding doctoral and postdoctoral research projects at universities worldwide. The PRC organizes this symposium every two years, at which international experts from science and industry present innovative and new applications of phospholipids. This year's symposium highlighted advancements in lipid-based gene and RNA delivery, anisotropic lipid nanoparticles, PEGylation challenges, tetraether lipids for drug delivery, ethical considerations in publishing, multifunctional lipopeptides, and phospholipid applications in therapeutics. Discussions also showcased award-winning research on optimizing liposome drug compatibility, reflecting the expanding role of phospholipids in pharmaceutical science.

Liposomal Formulations: A Recent Update

Liposome-based drug delivery technologies have showed potential in enhancing medication safety and efficacy. Innovative drug loading and release mechanisms highlighted in this review of next-generation liposomal formulations. Due to poor drug release kinetics and loading capacity, conventional liposomes have limited clinical use. Scientists have developed new liposomal carrier medication release control and encapsulation methods to address these limits. Drug encapsulation can be optimized by creating lipid compositions that match a drug's charge and hydrophobicity. By selecting lipids and adding co-solvents or surfactants, scientists have increased drug loading in liposomal formulations while maintaining stability. Nanotechnology has also created multifunctional liposomes with triggered release and personalized drug delivery. Surface modification methods like PEGylation and ligand conjugation can direct liposomes to disease regions, improving therapeutic efficacy and reducing off-target effects. In addition to drug loading, researchers have focused on spatiotemporal modulation of liposomal carrier medication release. Stimuli-responsive liposomes release drugs in response to bodily signals. Liposomes can be pH- or temperature-sensitive. To improve therapeutic efficacy and reduce systemic toxicity, researchers added stimuli-responsive components to liposomal membranes to precisely control drug release kinetics. Advanced drug delivery technologies like magnetic targeting and ultrasound. Pro Drug, RNA Liposomes approach may improve liposomal medication administration. Magnetic targeting helps liposomes aggregate at illness sites and improves drug delivery, whereas ultrasound-mediated drug release facilitates on-demand release of encapsulated medicines. This review also covers recent preclinical and clinical research showing the therapeutic promise of next-generation liposomal formulations for cancer, infectious diseases, neurological disorders and inflammatory disorders. The transfer of these innovative liposomal formulations from lab to clinical practice involves key difficulties such scalability, manufacturing difficulty, and regulatory limits.

Remote loading in liposome: a review of current strategies and recent developments

Liposomes have gained prominence as nanocarriers in drug delivery, and the number of products in the market is increasing steadily, particularly in cancer therapeutics. Remote loading of drugs in liposomes is a significant step in the translation and commercialization of the first liposomal product. Low drug loading and drug leakage from liposomes is a translational hurdle that was effectively circumvented by the remote loading process. Remote loading or active loading could load nearly 100% of the drug, which was not possible with the passive loading procedure. A major drawback of conventional remote loading is that only a very small percentage of the drugs are amenable to this method. Therefore, methods for drug loading are still a problem for several drugs. The loading of multiple drugs in liposomes to improve the efficacy and safety of nanomedicine has gained prominence recently with the introduction of a marketed formulation (Vyxeos) that improves overall survival in acute myeloid leukemia. Different strategies for modifying the remote loading process to overcome the drawbacks of the conventional method are discussed here. The review aims to discuss the latest developments in remote loading technology and its implications in liposomal drug delivery.

Liposomal Copermeation Assay Reveals Unexpected Membrane Interactions of Commonly Prescribed Drugs

The permeation of small molecules across biological membranes is a crucial process that lies at the heart of life. Permeation is involved not only in the maintenance of homeostasis at the cell level but also in the absorption and biodistribution of pharmacologically active substances throughout the human body. Membranes are formed by phospholipid bilayers that represent an energy barrier for permeating molecules. Crossing this energy barrier is assumed to be a singular event, and permeation has traditionally been described as a first-order kinetic process, proportional only to the concentration gradient of the permeating substance. For a given membrane composition, permeability was believed to be a unique property dependent only on the permeating molecule itself. We provide experimental evidence that this long-held view might not be entirely correct. Liposomes were used in copermeation experiments with a fluorescent probe, where simultaneous permeation of two substances occurred over a single phospholipid bilayer. Using an assay of six commonly prescribed drugs, we have found that the presence of a copermeant can either enhance or suppress the permeation rate of the probe molecule, often more than 2-fold in each direction. This can have significant consequences for the pharmacokinetics and bioavailability of commonly prescribed drugs when used in combination and provide new insight into so-far unexplained drug-drug interactions as well as changing the perspective on how new drug candidates are evaluated and tested.

Enhancing Solubility and Bioefficacy of Stilbenes by Liposomal Encapsulation-The Case of Macasiamenene F

Stilbenes in food and medicinal plants have been described as potent antiphlogistic and antioxidant compounds, and therefore, they present an interesting potential for the development of dietary supplements. Among them, macasiamenene F (MF) has recently been shown to be an effective anti-inflammatory and cytoprotective agent that dampens peripheral and CNS inflammation in vitro. Nevertheless, this promising molecule, like other stilbenes and a large percentage of drugs under development, faces poor water solubility, which results in trickier in vivo administration and low bioavailability. With the aim of improving MF solubility and developing a form optimized for in vivo administration, eight types of conventional liposomal nanocarriers and one type of PEGylated liposomes were formulated and characterized. In order to select the appropriate form of MF encapsulation, the safety of MF liposomal formulations was evaluated on THP-1 and THP-1-XBlue-MD2-CD14 monocytes, BV-2 microglia, and primary cortical neurons in culture. Furthermore, the cellular uptake of liposomes and the effect of encapsulation on MF anti-inflammatory effectiveness were evaluated on THP-1-XBlue-MD2-CD14 monocytes and BV-2 microglia. MF (5 mol %) encapsulated in PEGylated liposomes with an average size of 160 nm and polydispersity index of 0.122 was stable, safe, and the most promising form of MF encapsulation keeping its cytoprotective and anti-inflammatory properties.

Unraveling the Multifaceted Roles of Extracellular Vesicles: Insights into Biology, Pharmacology, and Pharmaceutical Applications for Drug Delivery

Extracellular vesicles (EVs) are nanoparticles released from various cell types that have emerged as powerful new therapeutic option for a variety of diseases. EVs are involved in the transmission of biological signals between cells and in the regulation of a variety of biological processes, highlighting them as potential novel targets/platforms for therapeutics intervention and/or delivery. Therefore, it is necessary to investigate new aspects of EVs' biogenesis, biodistribution, metabolism, and excretion as well as safety/compatibility of both unmodified and engineered EVs upon administration in different pharmaceutical dosage forms and delivery systems. In this review, we summarize the current knowledge of essential physiological and pathological roles of EVs in different organs and organ systems. We provide an overview regarding application of EVs as therapeutic targets, therapeutics, and drug delivery platforms. We also explore various approaches implemented over the years to improve the dosage of specific EV products for different administration routes.

Lipid-Based Nanoparticles for Drug/Gene Delivery: An Overview of the Production Techniques and Difficulties Encountered in Their Industrial Development

Over the past decade, the therapeutic potential of nanomaterials as novel drug delivery systems complementing conventional pharmacology has been widely acknowledged. Among these nanomaterials, lipid-based nanoparticles (LNPs) have shown remarkable pharmacological performance and promising therapeutic outcomes, thus gaining substantial interest in preclinical and clinical research. In this review, we introduce the main types of LNPs used in drug formulations such as liposomes, nanoemulsions, solid lipid nanoparticles, nanostructured lipid carriers, and lipid polymer hybrid nanoparticles, focusing on their main physicochemical properties and therapeutic potential. We discuss computational studies and modeling techniques to enhance the understanding of how LNPs interact with therapeutic cargo and to predict the potential effectiveness of such interactions in therapeutic applications. We also analyze the benefits and drawbacks of various LNP production techniques such as nanoprecipitation, emulsification, evaporation, thin film hydration, microfluidic-based methods, and an impingement jet mixer. Additionally, we discuss the major challenges associated with industrial development, including stability and sterilization, storage, regulatory compliance, reproducibility, and quality control. Overcoming these challenges and facilitating regulatory compliance represent the key steps toward LNP's successful commercialization and translation into clinical settings.

Research progress of nanovaccine in anti-tumor immunotherapy

Tumor vaccines aim to activate dormant or unresponsive tumor-specific T lymphocytes by using tumor-specific or tumor-associated antigens, thus enhancing the body's natural defense against cancer. However, the effectiveness of tumor vaccines is limited by the presence of tumor heterogeneity, low immunogenicity, and immune evasion mechanisms. Fortunately, multifunctional nanoparticles offer a unique chance to address these issues. With the advantages of their small size, high stability, efficient drug delivery, and controlled surface chemistry, nanomaterials can precisely target tumor sites, improve the delivery of tumor antigens and immune adjuvants, reshape the immunosuppressive tumor microenvironment, and enhance the body's anti-tumor immune response, resulting in improved efficacy and reduced side effects. Nanovaccine, a type of vaccine that uses nanotechnology to deliver antigens and adjuvants to immune cells, has emerged as a promising strategy for cancer immunotherapy due to its ability to stimulate immune responses and induce tumor-specific immunity. In this review, we discussed the compositions and types of nanovaccine, and the mechanisms behind their anti-tumor effects based on the latest research. We hope that this will provide a more scientific basis for designing tumor vaccines and enhancing the effectiveness of tumor immunotherapy.

Viscoelasticity of Liposomal Dispersions

Janus-faced viscoelastic gelling agents-possessing both elastic and viscous characteristics-provide materials with unique features including strengthening ability under stress and a liquid-like character with lower viscosities under relaxed conditions. The mentioned multifunctional character is manifested in several body fluids such as human tears, synovial liquids, skin tissues and mucins, endowing the fluids with a special physical resistance property that can be analyzed by dynamic oscillatory rheology. Therefore, during the development of pharmaceutical or cosmetical formulations-with the intention of mimicking the physiological conditions-rheological studies on viscoelasticity are strongly recommended and the selection of viscoelastic preparations is highlighted. In our study, we aimed to determine the viscoelasticity of various liposomal dispersions. We intended to evaluate the impact of lipid concentration, the presence of cholesterol or 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and the gelling agents polyvinyl alcohol (PVA) and hydroxyethylcellulose (HEC) on the viscoelasticity of vesicular systems. Furthermore, the effect of two model drugs (phenyl salicylate and caffeine) on the viscoelastic behavior of liposomal systems was studied. Based on our measurements, the oscillation rheological properties of the liposomal formulations were influenced both by the composition and the lamellarity/size of the lipid vesicles.