A Comparison of Cellular Uptake Mechanisms, Delivery Efficacy, and Intracellular Fate between Liposomes and Extracellular Vesicles

A key aspect for successful drug delivery via lipid-based nanoparticles is their internalization in target cells. Two prominent examples of such drug delivery systems are artificial phospholipid-based carriers, such as liposomes, and their biological counterparts, the extracellular vesicles (EVs). Despite a wealth of literature, it remains unclear which mechanisms precisely orchestrate nanoparticle-mediated cargo delivery to recipient cells and the subsequent intracellular fate of therapeutic cargo. In this review, internalization mechanisms involved in the uptake of liposomes and EVs by recipient cells are evaluated, also exploring their intracellular fate after intracellular trafficking. Opportunities are highlighted to tweak these internalization mechanisms and intracellular fates to enhance the therapeutic efficacy of these drug delivery systems. Overall, literature to date shows that both liposomes and EVs are predominantly internalized through classical endocytosis mechanisms, sharing a common fate: accumulation inside lysosomes. Studies tackling the differences between liposomes and EVs, with respect to cellular uptake, intracellular delivery and therapy efficacy, remain scarce, despite its importance for the selection of an appropriate drug delivery system. In addition, further exploration of functionalization strategies of both liposomes and EVs represents an important avenue to pursue in order to control internalization and fate, thereby improving therapeutic efficacy

Liposomes and Extracellular Vesicles as Drug Delivery Systems:A Comparison of Composition, Pharmacokinetics, and Functionalization

Over the past decades, lipid-based nanoparticle drug delivery systems (DDS) have caught the attention of researchers worldwide, encouraging the field to rapidly develop improved ways for effective drug delivery. One of the most prominent examples is liposomes, which are spherical shaped artificial vesicles composed of lipid bilayers and able to encapsulate both hydrophilic and hydrophobic materials. At the same time, biological nanoparticles naturally secreted by cells, called extracellular vesicles (EVs), have emerged as promising more complex biocompatible DDS. In this review paper, the differences and similarities in the composition of both vesicles are evaluated, and critical mediators that affect their pharmacokinetics are elucidate. Different strategies that have been assessed to tweak the pharmacokinetics of both liposomes and EVs are explored, detailing the effects on circulation time, targeting capacity, and cytoplasmic delivery of therapeutic cargo. Finally, whether a hybrid system, consisting of a combination of only the critical constituents of both vesicles, could offer the best of both worlds is discussed. Through these topics, novel leads for further research are provided and, more importantly, gain insight in what the liposome field and the EV field can learn from each other

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

Extracellular vesicles and soluble factors secreted by lung fibroblasts support alveolar organoid formation

Rationale: COPD is characterized by progressive and irreversible airflow limitation as a result of enhanced tissue destruction and defective tissue repair. As current therapeutics do not alter disease progression, new therapies that reactivate lung repair are needed. The secretome of fibroblasts, composed of Extracellular Vesicles (EVs) and other soluble factors (SF), has been linked to alveolar regeneration. We aimed to elucidate the supportive function of lung fibroblast-derived EVs and SF on the regenerative potential of alveolar epithelial progenitor cells in an organoid model.Methods: EVs and SF were purified using ultrafiltration and size exclusion chromatography. Mouse organoids were obtained by co-culturing 10,000 alveolar EpCAM+ cells with 2,500 lung fibroblasts, and then treated with EVs (109 EVs/ml) or SF (30 µg/ml). On day 14, number and size of the organoids was determined, as was the number of differentiated alveolar organoids.Results: Single treatment with EVs or SF increased organoid count, i.e. a 29.50% ± 8.11% increase for EVs and 33.00% ± 20.34% for SF. Neither treatment with EVs nor SF affected organoid size. Immunostaining for prosurfactant protein C revealed that the alveolar organoid count was significantly enhanced upon single treatment with EVs or SF. In addition, consecutive treatment for 14 days with EVs or SF resulted in enhanced organoid count (i.e. a 58.17% ± 39.60% and 91.67% ± 33.28% increase respectively) and size (i.e. a 36.50% ± 10.46% and 37.50% ± 27.02% increase respectively).Conclusions: Lung fibroblast-derived EVs and SF support alveolar epithelial organoid formation, making them an interesting potential treatment to pursue for COPD

Trends in psychostimulant drug use among adults in the Netherlands

Background Use of psychostimulants among children and adolescents receives a lot of attention. However, less is known about the use of these drugs among adults. The aim of our study was to describe trends in the use of psychostimulants among adults over time. Methods Data on adults (≥ 18 years), receiving two or more prescriptions for a psychostimulant drug (ATC-code N06BA; excluding modafanil) within 12 months, were selected from the IADB, a Dutch database of filled prescriptions (59 public pharmacies, about 600.000 patients). We calculated both the number of new users as well as the total number of users of psychostimulants in 2004-2014. Furthermore, we determined the most commonly prescribed psychostimulant drug and whether the psychostimulant was initiated by GP or medical specialist. Results The proportion of psychostimulants users (methylphenidate, dexamphetamine and amphetamine) increased from 1,5 per 1000 adults in 2004 to 7,8 per 1000 adults in 2014. Users were mainly male (63,0%) and methylphenidate predominated (85,7%). The proportion of new users of these drugs increased from 0,5 to 1,5 per 1000 adults. The largest increase was observed among young adults (< 30 year). Since 2012, the increase in new users seems to stabilize. Around 40% of new treatments were initiated by GPs. Conclusion The large increase in use of psychostimulants seems mainly due to an increase in the proportion of new users, especially among young adults. As psychostimulants are only approved for the treatment of ADHD among children (>6 years) and adolescents, short and long term effects and side effects of these drugs need to be assessed in the adult population

Differentiation and on axon-guidance chip culture of human pluripotent stem cell-derived peripheral cholinergic neurons for airway neurobiology studies

Airway cholinergic nerves play a key role in airway physiology and disease. Inasthma and other diseases of the respiratory tract, airway cholinergic neuronsundergo plasticity and contribute to airway hyperresponsiveness and mucussecretion. We currently lack human in vitro models for airway cholinergicneurons. Here, we aimed to develop a human in vitro model for peripheralcholinergic neurons using human pluripotent stem cell (hPSC) technology.hPSCs were differentiated towards vagal neural crest precursors andsubsequently directed towards functional airway cholinergic neurons usingthe neurotrophin brain-derived neurotrophic factor (BDNF). Cholinergicneurons were characterized by ChAT and VAChT expression, and respondedto chemical stimulation with changes in Ca2+ mobilization. To culture thesecells, allowing axonal separation from the neuronal cell bodies, a twocompartment PDMS microfluidic chip was subsequently fabricated. The twocompartments were connected via microchannels to enable axonal outgrowth.On-chip cell culture did not compromise phenotypical characteristics of thecells compared to standard culture plates. When the hPSC-derived peripheralcholinergic neurons were cultured in the chip, axonal outgrowth was visible,while the somal bodies of the neurons were confined to their compartment.Neurons formed contacts with airway smooth muscle cells cultured in theaxonal compartment. The microfluidic chip developed in this study represents ahuman in vitro platform to model neuro-effector interactions in the airways thatmay be used for mechanistic studies into neuroplasticity in asthma and otherlung diseases

A transcriptomics-guided drug target discovery strategy identifies receptor ligands for lung regeneration

Currently, there is no pharmacological treatment targeting defective tissue repair in chronic disease. Here, we used a transcriptomics-guided drug target discovery strategy using gene signatures of smoking-associated chronic obstructive pulmonary disease (COPD) and from mice chronically exposed to cigarette smoke, identifying druggable targets expressed in alveolar epithelial progenitors, of which we screened the function in lung organoids. We found several drug targets with regenerative potential, of which EP and IP prostanoid receptor ligands had the most profound therapeutic potential in restoring cigarette smoke–induced defects in alveolar epithelial progenitors in vitro and in vivo. Mechanistically, we found, using single-cell RNA sequencing analysis, that circadian clock and cell cycle/apoptosis signaling pathways were differentially expressed in alveolar epithelial progenitor cells in patients with COPD and in a relevant model of COPD, which was prevented by prostaglandin E2 or prostacyclin mimetics. We conclude that specific targeting of EP and IP receptors offers therapeutic potential for injury to repair in COPD